MODEL 25HPV

INSTRUCTION MANUALPart No. 910-215A3/20/04

COPYRIGHT 2004 BY R/D TECH, INC. All rights reserved.

No part of this manual may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopying, recording, or by any information storage and retrieval system, without the written permission of PanametricsJkaqqj, except where permitted by law. For information address: info@Panametrics-NDT.com.

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Printed in the United States of America

910-215B February 2004PREFACE

The Model 25HPV Ultrasonic Gage has been designed and manufactured as a precision instrument. Under normal working conditions it will provide long, trouble-free service.

Damage in transit - Inspect the unit thoroughly immediately upon receipt for evidence of external or internal damage that may have occurred during shipment. Notify the carrier making the delivery immediately of any damage, since the carrier is normally liable for damage in shipment. Preserve packing materials, waybills, and other shipping documentation in order to establish damage claims. After notifying the carrier, contact Panametrics-NDTTM so that we may assist in the damage claims, and provide replacement equipment, if necessary.

WARRANTY

Panametrics-NDT guarantees the Model 25HPV to be free from defects in materials and workmanship for a period of two years (twenty-four months) from date of shipment. The warranty only covers equipment that has been used in a proper manner as described in this instruction manual and has not been subjected to excessive abuse, attempted unauthorized repair, or modification. DURING THIS WARRANTY PERIOD, PANAMETRICS-NDT LIABILITY IS STRICTLY LIMITED TO REPAIR OR REPLACEMENT OF A DEFECTIVE UNIT AT ITS DISCRETION. Panametrics-NDT does not warrant the Model 25HPV to be suitable for intended use, and assumes no responsibility for unsuitability for intended use. Panametrics-NDT accepts no liability for consequential or incidental damages including damage to property and/or personal injury.This warranty does not include the transducer, transducer cable, charger, or battery. The customer will pay shipping expense to the Panametrics-NDT plant for warranty repair; Panametrics-NDT will pay for the return of the repaired equipment. (For instruments not under warranty, the customer will pay shipping expenses both ways.)Panametrics-NDT offers an optional third year warranty coverage, under the same terms, at the time of purchase.

Panametrics-NDT reserves the right to modify all products without incurring the responsibility for modifying previously manufactured products. Panametrics-NDT does not assume any liability for the results of particular installations, as these circumstances are not within our control.MODEL 25HPV i

910-215B February 2004TABLE OF CONTENTS

1 GENERAL INFORMATION............................................................................................... 1-12 BASIC OPERATION............................................................................................................. 2-1

2.1 Initial Setup.................................................................................................................... 2-13 SETUP AND CALIBRATION .............................................................................................. 3-1

3.1 Measurement Mode Selection (Velocity or Thickness) ................................................ 3-13.2 Choosing a Default or User-Defined Setup ................................................................... 3-13.3 Calibration ..................................................................................................................... 3-2

3.3.1 One Point Calibration (Velocity Measurement Mode Only).............................. 3-23.3.2 Two Point Calibration (Velocity or Thickness Measurement Mode)................. 3-33.3.3 Making Velocity Measurements (Velocity Measurement Mode) ..................... 3-4

3.3.3.1 Optional HPV/C Digital Caliper ..................................................................3-43.3.4 Making Thickness Measurements (Thickness Measurement Mode) ................. 3-5

3.4 Custom Setups ............................................................................................................... 3-53.4.1 Creating a Custom Setup .................................................................................... 3-5

4 GAGE FEATURES ................................................................................................................ 4-14.1 High/Low Alarm............................................................................................................ 4-14.2 Auto Shutoff .................................................................................................................. 4-24.3 Beeper Tone................................................................................................................... 4-34.4 Velocity/Thickness Display Blank or Hold ................................................................... 4-34.5 Calibration Lock ............................................................................................................ 4-34.6 Differential Display ....................................................................................................... 4-44.7 Language........................................................................................................................ 4-64.8 Measurement Display Update Rate ............................................................................... 4-64.9 Decimal Point ................................................................................................................ 4-74.10 Measurement Reset...................................................................................................... 4-74.11 Master Reset ................................................................................................................ 4-9

5 SCREEN DISPLAY FORMATS .......................................................................................... 5-15.1 Backlight........................................................................................................................ 5-15.2 Contrast.......................................................................................................................... 5-25.3 Measurement Screen...................................................................................................... 5-2

5.3.1 Measured Velocity/Thickness Value Area ......................................................... 5-25.3.2 First Status Line .................................................................................................. 5-25.3.3 Second Status Line.............................................................................................. 5-35.3.4 Fourth Status Line............................................................................................... 5-3

5.4 Calibration Screen ......................................................................................................... 5-45.4.1 Calibration Velocity Value Area ........................................................................ 5-45.4.2 First Status Line .................................................................................................. 5-4MODEL 25HPV iii

February 2004 910-215B5.4.3 Fourth Status Line............................................................................................... 5-45.5 Application Setup Screens ............................................................................................. 5-5

5.5.1 Application Setup List ........................................................................................ 5-55.5.2 Setup Parameter List ........................................................................................... 5-65.5.3 PC Scope Screen Format .................................................................................... 5-6

5.6 View/Set Screen............................................................................................................. 5-75.7 Special Mode Screens.................................................................................................... 5-8

5.7.1 Special Mode Selection Screen........................................................................... 5-95.7.2 Parameter or Function Screen............................................................................. 5-9

5.8 Status Screen................................................................................................................ 5-105.9 Error Help Screen ........................................................................................................ 5-10

6 TECHNICAL SPECIFICATIONS ....................................................................................... 6-16.1 Measurement Mode ....................................................................................................... 6-16.2 Application Setups......................................................................................................... 6-26.3 General........................................................................................................................... 6-66.4 Battery and Charger ....................................................................................................... 6-66.5 Special Gage Functions ................................................................................................. 6-7

7 BATTERY............................................................................................................................... 7-17.1 Low Battery ................................................................................................................... 7-17.2 Charging Batteries ......................................................................................................... 7-17.3 Changing Battery Pack .................................................................................................. 7-27.4 Optional Battery Pack.................................................................................................... 7-2

8 THEORY OF OPERATION .......................................................................................................... 8-19 APPLICATIONS NOTES...................................................................................................... 9-1

9.1 Measurement Mode ....................................................................................................... 9-19.2 Transducer Selection...................................................................................................... 9-29.3 Factors Affecting Performance and Accuracy............................................................... 9-29.4 Couplants ....................................................................................................................... 9-49.5 High Temperature Measurements.................................................................................. 9-59.6 Cable Lengths ................................................................................................................ 9-69.7 Waveform Displays Via PC Scope ................................................................................ 9-69.8 Pulser/Receiver and Gating Adjustments ...................................................................... 9-6

9.8.1 Pulser Power ....................................................................................................... 9-79.8.2 Maximum Gain ................................................................................................... 9-79.8.3 Initial Gain .......................................................................................................... 9-79.8.4 Main Bang Blank ................................................................................................ 9-89.8.5 Echo Window...................................................................................................... 9-89.8.6 Detect Mode........................................................................................................ 9-89.8.7 Echo 1 Detect, Echo 2 Detect ............................................................................. 9-99.8.8 Interface Blank.................................................................................................... 9-9iv MODEL 25HPV

910-215B February 20049.8.9 Mode 3 Echo Blank .......................................................................................... 9-109.8.10 TDG Slope ...................................................................................................... 9-10

10 MAINTENANCE & TROUBLESHOOTING................................................................. 10-110.1 Basic Maintenance..................................................................................................... 10-110.2 Transducers................................................................................................................ 10-110.3 Battery Care ............................................................................................................... 10-110.4 Error Messages .......................................................................................................... 10-210.5 Battery and Charger Problems................................................................................... 10-210.6 Measurement Problems ............................................................................................. 10-210.7 Diagnostic Self Tests ................................................................................................. 10-2

10.7.1 Display Test .................................................................................................... 10-310.7.2 Keyboard Test................................................................................................. 10-310.7.3 Hardware Test................................................................................................. 10-3

10.8 Software Upgrades..................................................................................................... 10-310.9 Customer Service....................................................................................................... 10-410.10 Repair Service.......................................................................................................... 10-410.11 Replacement Parts & Accessories ........................................................................... 10-4

APPENDIX ISOUND VELOCITIES APPENDIX IIPC SCOPE INTERFACE APPENDIX IIIKEYBOARD FUNCTIONSMODEL 25HPV v

910-215B February 20041 GENERAL INFORMATION

The Panametrics-NDTTM Model 25HPV is a state-of-the-art, hand-held ultrasonic velocity/thickness gage. This precision microprocessor-based instrument uses pulse-echo techniques to measure material velocity/thickness when both sides of the test material are not easily accessible.

The Model 25HPV is designed with one basic goal in mindsimplicity of operation. A wide velocity/thickness range makes the Model 25HPV an extremely versatile gage especially when utilizing the gages three modes of operation with contact, delay line, and immersion transducers.

Transducer Auto-Recall, one of the gages unique features, simplifies gaging by allowing both Standard Default and Custom Stored Transducer Setups. In general, one of the five Default Transducer Setups is adequate for most applications. However, if your application requires a special setup, the Model 25HPV offers five Custom Setup locations that may be programmed by the user or by Panametrics-NDT.

The Model 25HPV is equipped with a serial communications port for connecting the gage to either a DOS PC Scope program or new WIN25DL PC Scope software. Both programs allow the user to make adjustments to transducer setups while viewing the RF Waveforms.Other features include:

Thickness range: 0.050-25.00 in (1.25-635mm), depending on material and transducer type

Large backlit display High-Low Alarm functions Differential Mode Velocity Resolution 0.0001 in/sec (00.001mm/sec) Thickness Resolution 0.001 in (00.01mm) Display HOLD/BLANK mode Long battery life English/Metric units (inches or millimeters, or in/sec or mm/sec) with instant

conversion Multiple Languages (English, French, German, Spanish) Optional RF Waveform Oscilloscope output to your computer Rugged case and a sealed keypad that is color-coded and provides tactile and audible

feedback Semi-automatic keyboard calibration Internal Self-Test Modes Calibration lockout function to prevent accidental change to calibration or

measurement modeMODEL 25HPV 1-1

February 2004 910-215BIn addition, special prompts inform the user of instrument conditions such as: Active Transducer Type and Setup, Low Battery, Loss of Signal (LOS), Calibration Mode, Alarms, and Differential Mode.

Panametrics-NDTTM offers a wide variety of broadband contact, delay line and immersion transducers for use with the Model 25HPV to permit optimum application of the gage on most engineering materials. For applications assistance, please consult Panametrics-NDTor refer to Table 6-1 on page 6-3 of this manual for a list of Default Transducer Setups and approximate thickness ranges.1-2 MODEL 25HPV

910-215B February 2004MODEL 25HPV 1-3

February 2004 910-215B2 BASIC OPERATION

The purpose of this section is to demonstrate how easy it is to make basic velocity/thickness measurements with the Model 25HPV gage. The unit ships from the factory containing default conditions for the transducer(s) you have purchased. Parameters may be changed after becoming familiar with the more sophisticated gage features.

2.1 Initial Setup

Follow the initial setup procedure when operating the gage for the first time. To begin the initial setup:

1. Plug the transducer cable into the transducer connector located on the top panel of the Model 25HPV.

2. Connect the transducer to the other end of the cable.

3. Press the [ON/OFF] key to turn the gage on. The display will briefly show the following message:

Ensure that the probe type shown above matches the transducer you have attached to the gage. This part number is engraved on the back or side of the transducer.

Note: If the probe type does not match the transducer, please refer to section 3.2 of this manual.

Approximately three seconds after the gage is turned on, one of the following screens will appear depending whether the gage is set to the Velocity or Thickness mode:

PANAMETRICS-NDTTMModel 25HPV

SETUP: DEF-M1036PROBE: M10362-1 MODEL 25HPV

910-215B February 200404. The current units are indicated on the right side of the display. To alternate measurement units between inches (in/sec) and millimeters (mm/sec) press the [IN/MM] key. The gage is now ready to make measurements based on the default settings and included test block.

Note: The initial setup is not a substitute for doing a proper calibration. For materials other than the included test block, see Section 3Setup and Calibration.

Velocity Mode Thickness ModeMODEL 25HPV 2-2

February 2004 910-215B2-3 MODEL 25HPV

910-215B February 20043 SETUP AND CALIBRATION

3.1 Measurement Mode Selection (Velocity or Thickness)The 25HPV Ultrasonic Velocity/Thickness gage can operate in either a Velocity or Thickness mode. In Velocity mode, which is the default measurement mode, the gage calculates and displays the material velocity based on a time of flight measurement and user entered Ref Value (Thickness). The 25HPV can also operate like a standard ultrasonic thickness gage when the Measurement mode is set to the Thickness mode.

Selecting Measurement mode:1. Turn unit on.

2. Press [2nd F], [IN/MM] (SP MODE).3. Press the [ ] and [ ] keys to select GAGE SETUP and press [ENTER].4. Press the [ ] and [ ] keys to highlight MEASUREMENT.5. Press the [ ] or [ ] key to select either THK (Thickness Mode) or VEL (Velocity

Mode) and press [MEAS].

3.2 Choosing a Default or User-Defined Setup

The Model 25HPV has the ability to use a wide variety of transducers through the Application Recall feature. Stored within the gage are five Pre-Defined and five User-Defined application setups that provide maximum flexibility for a wide range of applications. The Pre-Defined setups always remain in the gage as defaults and cannot be removed. This section discusses how to choose an appropriate stored transducer setup and how to calibrate the Model 25HPV for a specific application.

1. Select a transducer for the desired application and connect it to the gage.

Note: To determine an appropriate transducer, please refer to page 6-3, Table 6.1Application Setup Name and Application. Use the table as a guideline only; exact thickness ranges will vary depending on the application.

2. While the gage is in the Measure mode, press [RECALL SETUP]. The following screen will appear:

DEF-M106DEF-M109DEF-M110DEF-M1036

DEF-M2008MODEL 25HPV 3-1

February 2004 910-215B3. Use the [ ] and [ ] keys to scroll through the available stored setups until the correct setup for the application is highlighted. A complete list of the available choices is as follows:

ACTIVEDEF-M106DEF-M109DEF-M110DEF-M1036DEF-M2008USER-1USER-2USER-3USER-4USER-5

Note: The setups listed as USER-1 through USER-5 may be renamed for special applications (see Section 3.4Custom Setups). For a complete description see Section 9Application Notes.

4. Once the correct setup is highlighted, press [MEAS]. This action automatically recalls the setup parameters for the chosen setup and brings the user back to the measure screen. Begin taking measurements.

3.3 Calibration

In order to calibrate the 25HPV velocity/thickness gage the user must determine the Zero Offset of the transducer and electronics. This process can be done in two ways: 1) a Single Point Calibration (Velocity Measurement mode only) using one sample where the mechanical thickness and sound velocity are known, or 2) a Two Point Calibration (Velocity or Thickness Measurement mode) using two samples where the mechanical thicknesses are known and the samples have the same material sound velocity.

Note: The gage comes with a two step steel block that can be used to perform a Two Point Calibration. Using this block will provide good accuracy for most velocity measurement applications. To achieve the highest degree of accuracy when using the 25HPV in Thickness Measurement mode, the user should calibrate on their own samples that represent their surface conditions and material geometry. If samples other than the one provided are used, the user must know the mechanical thickness of the samples, and samples must have the same material sound velocity. The thickness of these samples must be within the thickness measurement range for the transducer.

3.3.1 One Point Calibration (Velocity Measurement Mode Only)One Point Calibration requires one sample of known thickness and known Velocity.3-2 MODEL 25HPV

910-215B February 20041. Press [RECALL SETUP].2. Use the [ ] and [ ] keys to select the transducer and press [ENTER], or press [ENTER]

on the active transducer setup.

3. Use the [ ] and [ ] keys to select Ref Vel and press [ENTER].4. Use the [ ] and [ ] keys to enter the known Ref Velocity of the block and press

[MEAS].5. Press [MEAS] once again to exit the App Setup screen.6. Couple to a sample with the entered Ref Velocity and known thickness.

7. Press [CAL THICK] or [CAL THIN]. The gage will display a thickness.8. When the thickness reading is steady, press [ENTER].9. Use the [ ] and [ ] keys to enter the known thickness.10. Press the [MEAS] key to complete the calibration process.

3.3.2 Two Point Calibration (Velocity or Thickness Measurement Mode)Two Point Calibration requires two samples of the same material velocity and known thickness. The velocity value does not need to be known.

1. Couple to a thick sample and press [CAL THICK]. The gage will display a thickness reading.

2. When the thickness reading is steady, press [ENTER].3. Use the [ ] and [ ] keys to enter the known thickness.4. Couple the transducer to a thin sample and press [CAL THIN]. The gage will display a

thickness reading.

5. When the thickness reading is steady, press [ENTER].6. Use the [ ] and [ ] keys to enter the known thickness.7. Press the [MEAS] key to complete the calibration.

Note: If the user presses the [MEAS] key after the [CAL THICK] key, the gage will automatically do a One Point Calibration using the current Ref Vel that is stored in the active setup.MODEL 25HPV 3-3

February 2004 910-215B3.3.3 Making Velocity Measurements (Velocity Measurement Mode)1. Perform a One Point or Two Point Calibration.

2. Press the [REF VALUE] key. The current Reference Thickness Value will be displayed in large characters in the center of the screen. If the samples thickness is different from this Reference Value, use the [ ] and [ ] keys to enter the new Reference Thickness Value.

3. Press [MEAS].4. The Ref Value will be shown on the 2nd line of the display.

5. Couple to a sample that has the same physical thickness as the Ref Value.

6. The gage will display the Velocity in the center of the screen.

3.3.3.1 Optional HPV/C Digital Caliper

1. Cable Connection

Remove the RS-232 environmental plug from the caliper, located in the RS-232 port above the Fowler Sylvac label on the caliper.

Insert the HPV/CC cable into the calipers RS-232 slot with the words OPTO RS 232 facing down.

Plug the other end of the HPV/CC cable into the RS-232 port of the 25HPV.

2. Setting up the Units on the HPV/C Digital Caliper

Press Set Button or Mode Button to turn ON the digital caliper. (To turn OFF the caliper: Press and Hold Set Button for 2 seconds.)

Press Mode Button and SET will be displayed (active for 3 seconds). Press Mode button twice to display UNIT (active for 3 seconds). Press Set Button to toggle between Inch and MM.

3. Setting up the 25HPV Velocity/Thickness Gage

Turn on the 25HPV. Press [2ndF], [IN/mm] (SP Mode). Use the or keys to highlight SP_2 Gage Setup, then press [ENTER]. Use the or keys to highlight MEASUREMENT. Use the or keys to set the mode to VEL (Note: the digital caliper only

works when the gage is in Velocity mode). Press [Meas] Setup and calibrate the 25HPV as described in Section 3 of the 25HPV manual.

4. Sending the Digital Caliper Thickness Reading to the 25HPV

Use the digital caliper to measure the thickness of the material then press Set Button and the displayed thickness value will be transferred to the 25HPV and be displayed in the REF VALUE Box.

Couple the transducer to the location that was mechanically measured and the 25HPV will display the velocity of the material.3-4 MODEL 25HPV

910-215B February 20043.3.4 Making Thickness Measurements (Thickness Measurement Mode)1. Perform a Two Point Calibration on sample representing the maximum and minimum

thickness range of the material to be tested.

2. Make sure the 25HPV is in Thickness Measurement mode (see Section 3.1).3. Apply couplant to the measurement location and couple the transducer to the sample and

the thickness should be shown on the display.

3.4 Custom Setups

The Model 25HPV contains five User-Defined setups for custom applications that cannot be measured with one of the five Pre-Defined setups. The gage may need adjustments to achieve optimum performance for certain special or custom applications. This section describes how to create and store new customized setups that are conveniently accessible and flexible.

Note: Adjustments to the Pulser/Receiver should be made only by a qualified technician who is familiar with the basic theory of Ultrasonic Gaging and the interpretation of Ultrasonic Waveforms. Many of these adjustments effect the range and/or measurement accuracy of the Model 25HPV. Adjustments should not be attempted without the use of a 25SM (PC Scope accessory) or WIN25DL to monitor Waveforms.

Uniquely, PC Scope allows the operator to view the Waveforms on a regular PC and does not require the use of an oscilloscope. For further information on how to use PC Scope, refer to the 25SM or WIN25DL User Manual.

Panametrics-NDTTM also offers free applications assistance from our Applications Lab. The lab is able to provide sample evaluations and specific custom parameter settings for special applications.

3.4.1 Creating a Custom Setup

1. Connect the 25SM Scope monitor box to the Model 25HPV and the PC. Run the DOS PC Scope or WIN25DL software. (Refer to the 25SM or WIN25DL User Manual for instructions.)

2. Press [RECALL SETUP] from the Measure screen to bring up the Application Setup screen.

3. Use the [ ] and [ ] keys to select one of the Pre-Defined setups that matches the transducer type, or Frequency and Diameter of the selected transducer.

DEF-M106DEF-M109DEF-M110

DEF-M2008MODEL 25HPV 3-5

February 2004 910-215B4. Press [ENTER] and the Detailed Setup Screen will be displayed:

5. If PC Scope is not being used, press the [ ] and [ ] keys to select individual setup parameters. After selecting parameters, continue to Step 6.

If PC Scope is being used, press [RECALL SETUP] to enter the PC Scope mode and one of the following screens will be displayed depending whether the gage is in Velocity or Thickness mode.

Use the [ ] and [ ] keys to select individual setup parameters. After selecting parameters, continue to Step 6. The following is a list of the available parameters that are adjustable.

SetupNameMBBlnkProbeTypeEchWindowRefVelDtectModeZeroEch1DtectPulserPWREch2DtectMaxGainI/FBlnkInitGainM3EchBlnkTDGSlope

Thickness Measurement ModeVelocity Measurement Mode3-6 MODEL 25HPV

910-215B February 20046. The operator may change the selected parameter by using available keystrokes shown in the Available Keys Field at the bottom of the display. See examples below:

The two examples above show the available arrow options. The [ ] and [ ] keys select a parameter while the [ ] and [ ] keys change the value of a parameter. In some cases (RefVel, Zero) the [ENTER] key must be pressed to change a parameter. There are many adjustable parameters, all following the same type of format. All available keys appear on the bottom of the screen.

Note: Once all parameters have been adjusted for a new application, store the setup so that it may be recalled at any time. If an adjusted setup is not stored it will be deleted when another setup is selected and the user will have to manually change the parameters again.

7. Press [2nd F], [RECALL SETUP] (Save Setup) to store the modified setup while either the Application Setup list or the Setup Parameter list is displayed.

The second line of this screen shows the original setup name used to create the custom setup (unless the Setup Name parameter has been changed). To change the Save_As: name to a new name, use the editing keys shown in the middle of the screen. The gage will use the new name to store and recall the custom application setup.

8. After creating a new name, press [ENTER] to confirm the name. Press [MEAS] at any time to return to the previous screen without changing the setup name or storing the setup.

Note: If you create a new custom setup, but dont change the name, the new setup will have the same name as the previous setup.

9. After the new name is confirmed the following screen will be displayed:

Available keys field Available keys fieldMODEL 25HPV 3-7

February 2004 910-215BThe third line of the screen shown above highlights the name of a custom setup location, which will be replaced by the new setup. Select a custom setup location to overwrite the new custom setup by using the [ ] or [ ] keys.

Note: All the USER-N locations are just place-holders that only repeat the default setup information, so they can be safely overwritten. Overwriting any of the DEF-XXX default setups is not possible.

10. Press [ENTER] to store the specified setup name in place of the specified location, or press the [MEAS] key to escape without storing the setup.3-8 MODEL 25HPV

910-215B February 20044 GAGE FEATURES

The Model 25HPV has many additional velocity/thickness measurement features other than those discussed in Section 2 and 3 that make the gage a reliable, versatile instrument. This section outlines each features benefits and functionality.

4.1 High/Low Alarm

The Alarm feature provides a warning for the operator when a velocity/thickness reading goes above or below a programmable alarm level. These levels are known as Setpoint Values. The Alarm must be turned on from the gages Alarm Measure Mode in order for this feature to work. When the alarm is activated and a displayed velocity/thickness reading extends beyond the designated range, an alarm condition occurs sounding audible beeps and visual indicators. The audible beep stops during LOS (Loss of Signal).The images below show examples of a visual indicator when a low measure alarm condition occurs. A LOW or HIGH message on the bottom of the screen replaces the standard ALRM indicator.

To view and/or change the Alarm Setpoint Values:1. Press the [ALARM] key from any Measure mode. The existing Low Alarm Setpoint

Value will be displayed with the word LOW indicated. Use the [ ] and [ ] keys to change the value.

2. Press the [ALARM] key again to display the existing High Alarm Setpoint Value. Use the [ ] and [ ] keys to change the value, or press [ENTER] to accept it. If the first number entered is higher than the following number, the gage will intuitively interpret the lower number as the Low Alarm Setpoint Value and the higher value as the High Alarm Setpoint Value.

Velocity Measurement Mode Thickness Measurement Mode

LOW MEASURE ALARM CONDITIONMODEL 25HPV 4-1

February 2004 910-215BAlso note that Alarm Setpoint Values entered in one system of units (i.e. metric or inches) will be displayed as the closest equivalent value if an alternate unit is selected.

3. Press [MEAS] while in the view/set Alarm Setpoint Value mode to select the Alarm Measure mode.

Note: If the previous mode was a Differential Measure mode, then pressing the [ALARM] key will disable the Differential mode.

4. Press the [ALARM] key to disable the alarm while in an Alarm Measure mode.

4.2 Auto Shutoff

By default, the gage turns off automatically after about six minutes when the gage remains idle. This safety feature prevents the battery from running low if the gage is left unattended for a long period of time without being turned off. The shutoff time period may be set from 6 to 18 minutes, or disabled entirely.

To view or change the Auto Shutoff parameters:1. Press [2nd F], [IN/MM] (SP Mode) to display a list of Special Modes.

a. Use the [ ] and [ ] keys to select SP-2 (Gage Setup). Press [ENTER].b. Use the [ ] and [ ] keys to select Inactive Time.c. Use the [ ] or [ ] keys to change the Inactive Time between OFF, 6 MIN, 12

MIN, or 18 MIN.

2. Disable the auto shutoff by choosing OFF for the Inactive Time parameter.

3. Press the [MEAS] key to return to the Measure mode.

0.2385 in/S4-2 MODEL 25HPV

910-215B February 20044.3 Beeper Tone

The Beeper sounds when any keys on the gage are pressed and certain actions occur. The Beeper is enabled (turned on) by default. If the Beeper is not desired, it may be disabled.

To enable or disable the beeper tone:1. Press [2nd F], [IN/MM] (SP mode) to display a list of Special Modes.2. Use the [ ] and [ ] keys to select SP-2 (Gage Setup). Press [ENTER].3. Use the [ ] and [ ] keys to select Beeper and use the [ ] or [ ] keys to choose ON

or OFF.

4. Press [MEAS] to return to the Measure mode.

4.4 Velocity/Thickness Display Blank or Hold

By default, the gage blanks its last measured and displayed velocity/thickness value when LOS occurs (Blank mode). In other words, when the gage stops reading a signal the screen will not show any velocity/thickness reading, thus appearing blank. The Hold function (Hold mode), on the other hand, freezes the last measured velocity/thickness even when LOS occurs.

To change to the Hold mode from the Blank mode:

1. Press [2nd F], [IN/MM] (SP mode).2. Use the [ ] and [ ] keys to select SP-2 (Gage Setup). Press [ENTER].3. Use the [ ] and [ ] keys to select HOLD/BLANK.4. Use the [ ] or [ ] keys to toggle between Hold and Blank.5. Press [MEAS] to return to the Measure mode.

4.5 Calibration Lock

The Calibration Lock protects calibration values and application setups so they cannot be altered, but may be viewed. However, all other gage setups can still be changed.

To enable the Calibration Lock:1. Press [2nd F], [IN/MM] (SP Mode).2. Use the [ ] and [ ] keys to select SP-2 (Gage Setup). Press [Enter].3. Use the [ ] and [ ] keys to select CAL LOCK.

4. Use the [ ] and [ ] keys to select ON. The Calibration Lock prompt CAL LOCKED will be displayed in the second field of the first status line indicating that the Calibration Lock is active.

6. Press [MEAS] to return to the Measure mode with the calibration locked.MODEL 25HPV 4-3

February 2004 910-215B4.6 Differential Display

The Differential Velocity/Thickness display shows a velocity/thickness reading as the difference between the actual Measured Velocity/Thickness and a user set Differential Reference Value as defined below:

(Differential Vel./Thick.) = (Measured Vel./Thick.) - (Differential Reference Vel./Thick.)

Differential Velocity/Thickness: Allows the user to view and change a Velocity/Thickness Differential Reference Value, and also to select the display of the Differential Velocity/Thickness.

Differential Reference Value: The units and resolution of the Differential Reference Value and the Differential Velocity/Thickness are the same as those selected for the velocity measurement.

The following Table shows the different thickness readings derived from the same sequence of four measurements when Differential Measure modes are selected and the gage is set to Thickness Measurement mode.

To view, set, or change the Differential Reference Value:1. Press the [2nd F], [ALARM] (DIFF) key while in the Measure mode. A screen titled

DIFFERENTIAL will display the current Differential Reference Value, which may be changed using the [ ] and [ ] keys. The Differential Reference Value display is shown below:

Table 4-1: Thickness Readings during Differential Measure Modes

MeasuredThickness

DifferentialReference Value

DifferentialThickness

0.070" 0.100" -0.030"

0.105" 0.100" 0.005"

0.120" 0.100" 0.020"

0.085" 0.100" -0.015"4-4 MODEL 25HPV

910-215B February 20042. To select the Differential Measure mode from the Set/View Differential mode, press [MEAS]. If the gage was in the Measure or Alarm Measure mode before [2nd F], [ALARM] (DIFF) was pressed, then the Differential Measure mode will be selected.

Note: Differential Measure and Alarm Measure are mutually exclusive modes and cannot be active simultaneously.

Differential Measure modes are indicated by the word MEAS in the fourth field of the first status line and the word DIFF in the third field of the bottom status line. The example below shows the Differential Measure mode while in the Thickness Measurement mode:

VIEWSET DIFFERENTIAL REFERENCE

Velocity Measurement Mode Thickness Measurement Mode MODEL 25HPV 4-5

February 2004 910-215B3. Return the gage to the Measure Mode from the Set/View Differential mode or any Differential Measure mode by pressing the [2nd F], [ALARM] (DIFF) key. The Differential Reference Value will be stored and can be recovered for later use.

4.7 Language

English is the default language in the Model 25HPV gage. However, it is easy to change the language specification to French, German, or Spanish. When a language other than English is specified, most text will be shown in the specified language, although some text will remain in English.

To change the default language:1. Press [2nd F], [IN/MM] (SP Mode).2. Use the [ ] and [ ] keys to select SP-2 (Gage Setup). Press [ENTER].3. Use the [ ] and [ ] keys to select the Language option and use the [ ] or [ ] keys to

select another language.

4. Press [MEAS] to return to the Measure mode.

4.8 Measurement Display Update Rate

The rate at which the measured velocity/thickness value is updated on the display may be adjusted between 1, 2, 5, or 10 measurements per second, averaging with or without QBAR (see Note below). The default measurement rate is 2 measurements per second.

Note: Averaging is used for the highest degree of accuracy/stability. A five measurement running average is calculated and displayed at a 10 measurement per second rate.

The QBAR (quality bar), is an indicator of measurement stability shown on the third status line. The length of the QBAR is proportional to the measurement stability. A short QBAR indicates relatively unstable readings, which vary from one to the next. A long QBAR indicates stable readings, that is, readings that do not vary from one another. Averaging with QBAR aids in finding optimum transducer coupling in some applications.

For each measured material a combination of factors affect how fast the least significant digit of the velocity/thickness value changes, such as:

measurement rate setting transducer type speed of transducer movement

In general, the operator should use a measurement rate and technique that yields a fast response to transducer placement and movement without encountering fluctuation from the least significant digit.4-6 MODEL 25HPV

910-215B February 2004To display the current Measurement Rate:1. Press [2nd F], [CAL THICK] (MEAS RATE). The rate will be displayed on the second

status line.

2. To change the Measurement Rate, press [ ] or [ ] until the desired rate is shown on the second status line. The available settings are:

Meas Rate = 1/secMeas Rate = 2/secMeas Rate = 5/secMeas Rate = 10/secAveraging - No QBARAveraging - QBAR

Measurements remain active during this time and rate changes occur immediately.

3. To remove the Measurement Rate display, press [MEAS].

4.9 Decimal Point

By default, the Decimal Point (.) is used for accurate velocity/thickness values in the Model 25HPV. The operator may choose to use a comma (,) instead of the period by changing the parameters.

To change the decimal point to the comma:1. Press [2nd F], [IN/MM], (SP Mode).2. Use the [ ] or [ ] keys to select SP-2 (Gage Setup). Press [ENTER].3. Use the [ ] or [ ] keys to select Decimal Point.4. Use the [ ] or [ ] keys to select either the period or comma.5. Press the [MEAS] key to return to the Measure mode.

4.10 Measurement Reset

The Measurement Reset restores the gage to the measurement default parameters. This may be a useful feature to new operators while becoming familiar with the advanced feature setups, as well as experienced operators to create an efficient short-cut to a known configuration. The measurement calibration and setup is NOT affected by Measurement Reset.MODEL 25HPV 4-7

February 2004 910-215BThe parameters will reset to the following:

Measure mode with Differential and Alarms turned off Differential Setpoint Value = 0.0 in/sec or 0.508mm/sec in Velocity mode,

or 0.000 in/mm in Thickness mode Low Alarm Setpoint Value = 0.0200 in/sec or mm/sec in Velocity mode, or

0.000 in/mm in Thickness mode High Alarm Setpoint Value = 0.6692 in/sec or 17.000mm/sec in Velocity

mode, or 25.000 in (635.00mm) in Thickness mode CAL function unlocked Measurement Update Rate = 2 per second Blank velocity/thickness display during LOS condition Backlight off LCD Contrast set to normal Inactive Time = 6 minutes Beeper ON

To perform the Measurement Reset:1. Press [2nd F], [IN/MM] (SP MODE).2. Use the [ ] or [ ] keys to select SP-3 (Gage Reset). Press [ENTER].3. Use the [ ] or [ ] keys to select Measure Reset. Press [ENTER]. The following screen

will be displayed:

4. Press the [ENTER] key to confirm the Measure Reset selection, or to go directly back to the selection screen by pressing [MEAS].(When the [ENTER] key is pressed, a beep and a message Reset Complete confirms that a Measure Reset has been performed and the reset selection screen is shown.)4-8 MODEL 25HPV

910-215B February 20044.11 Master Reset

The Master Reset function resets all of the gages parameters to default settings.

Note: This feature is a powerful tool; use with caution.

To perform a Master Reset:1. Press [2nd F], [IN/MM] (SP MODE).2. Use the [ ] or [ ] keys to select SP-3 (Gage Reset). Press [ENTER].3. Use the [ ] or [ ] keys to select Master Reset. Press [ENTER].4. Press the [ENTER] key to confirm the Master Reset selection, or to go directly back to the

selection screen by pressing [MEAS].(When the [ENTER] key is pressed, a beep and a message Reset Complete confirms that a Master Reset has been performed and the reset selection screen is shown.)

5. Press [MEAS] to return to the Measure mode, or go to the Special mode selection list and select Main Special Mode Menu.

Note: After a Master Reset, your last transducer setup remains as the active setup in the gage.MODEL 25HPV 4-9

910-215B February 20045 SCREEN DISPLAY FORMATS

The Model 25HPV shows the measured velocity/thickness and all other information on a 2.3"W x 1.6"H (58mm x 41mm) Liquid Crystal Display (LCD). The display is easily readable in normal working conditions, ambient lighting, and a wide range of temperatures. There is a switchable internal backlight to enable reading the display in low light conditions, as well as a contrast control to optimize display readability at extreme temperatures and poor lighting.

The screen display is a graphics type, which means that it can display different types of information in different formats. The Model 25HPV displays information in five basic screen formats.

1. Measurement Screen: Shows the velocity/thickness reading in large digits in the center of the display surrounded by other measurement information and gage conditions.

2. Calibration Screen: Similar to the Measurement Screen but is for Calibration.

3. Application Setup Screens (3):a. A list of measurement setups from which the proper setup for particular measurement

applications may be chosen.

b. A list of parameter values for each setup, which may be customized for unusual applications.

c. An active velocity/thickness measurement and a parameter value that allow changing the parameter value using the PC Scope.

4. View/Set Screen: Shows the value of a parameter such as Differential Reference or Velocity/Thickness in large digits in the center of the display with additional information on the top and bottom status lines.

5. Special Mode Screens (2): Allows normal gage measurements to be customized for special requirements. These screens also allow the gage to be reset to known default conditions and run tests on various internal parts of the gage.

5.1 Backlight

The gage displays the best contrast in bright light. However, the screen is easily readable in subdued light or even complete darkness by using the built-in electroluminescent backlight.

To turn on the display backlight:1. Press the key with the light bulb symbol. When the backlight is turned on, a light bulb symbol

on the gage display will appear above the units indicator.

2. The backlight may be switched off by pressing the light bulb key again.

Note: To prevent unnecessary drain on the battery, use the backlight only when needed. The backlight turns off when the gage is shut down, and after a Master or Measurement Reset.MODEL 25HPV 5-1

February 2004 910-215B5.2 Contrast

Normally, the display contrast requires no adjustment. However, at extreme temperatures, such as below 32F (0C) and above 104F (40C), contrast adjustment may be required.To adjust display contrast:

1. Press [2nd F], [LIGHT BULB] (LCD ADJ).2. Press [ ] to darken the display or [ ] to lighten the display.

To stop adjusting display contrast:1. Press either [MEAS] or [ENTER] to stop the [ ] and [ ] keys from adjusting contrast.2. Restore contrast to the default setting by performing a Measurement or Master Reset.

5.3 Measurement Screen

The Measurement Screen is displayed when the Model 25HPV is in the velocity/thickness measuring mode. The Measurement Screen is divided into several fields where particular types of information are located.

5.3.1 Measured Velocity/Thickness Value Area

The large area in the center of the screen is for displaying the measured velocity/thickness value including the selected units and resolution.

5.3.2 First Status Line

The first status line has three fields that are used in the Measurement Screen.

1. The basic Measurement Screen differs from other screens such as the PC Scope and Calibration screens because the first and second fields are blank, and the third field contains the prompt MEAS N (where N refers to the selected detection method).

2. The rightmost field of the first status line is only used to display the LOS (Loss Of Signal) prompt when the Model 25HPV cannot detect a signal from the transducer.5-2 MODEL 25HPV

910-215B February 20045.3.3 Second Status Line

When either Measurement Rate or Display Blank/Hold is selected, the status of those two functions is shown on the second status line.

5.3.4 Fourth Status Line

The leftmost field of the fourth status line is used to indicate that the [2nd F] key has been pressed. The Model 25HPV will interpret the next keystroke according the second function name printed above the keys on the keypad.

The second field shows the primary available keys for that function.

The third field is used to indicate the following:

The Alarm Measure mode is enabled, (ALRM) The Alarm Measure mode is enabled and the measurement is less than the low

setpoint, (flashing LOW) The Alarm Measure mode is enabled and the measurement is greater than the high

setpoint, (flashing HIGH) The Differential Measure mode is active, (DIFF)

The fourth field is used to indicate the occurrence of an operational error. Press [2nd F], [REF VALUE], (STATUS) for more information when E is displayed here.The rightmost field always shows an estimate of the remaining battery capacity (see Section 7.1).

MEAS RATE = 2/SEC

0.2230 in/SMODEL 25HPV 5-3

February 2004 910-215B5.4 Calibration Screen

The Calibration Screen, similar to the Measurement screen, is used during material sample calibrations. Please refer to the Calibration Screen below, which shows several field divisions where particular information is located.

5.4.1 Calibration Velocity Value Area

The large area in the center of the screen displays the measured or entered thickness value of the calibration sample(s).

5.4.2 First Status Line

The Calibration Screen uses three of the four first status line fields.

The second field indicates that Cal Thick or Cal Thin calibration is selected.

The third field indicates the detection method used to measure the calibration sample material by displaying MEAS N (where N is 1, 2, or 3).

The rightmost field of the first status line is only used to display the LOS prompt when the Model 25HPV cannot detect a signal from the transducer.

5.4.3 Fourth Status Line

The Calibration Screen uses four of the five fields of the fourth status line.

The leftmost field of the fourth status line indicates that the [2nd F] key has been pressed, and the gage will accept the secondary function from the next key pressed, which is shown above the keys on the keypad.

The second field shows the primary available keys for the selected function.

E

LOSVEL

MEAS 1MEAS 2MEAS 3

Indicates Loss of Signal

Calibration Measurement mode uses echo detection method 1, 2, or, 3

Cal Thick Calibration

4th Status Line

2nd Status Line (not used)

3rd Status Line (not used)

Calibration Thickness Value

1st Status Line

Keyboard 2ND Function

Available keysError

Battery capacity Keyboard 2ND Function5-4 MODEL 25HPV

910-215B February 2004 The third field is blank.

The fourth field indicates the occurrence of an operational error. Press [2nd F], [REF VALUE] (STATUS) for more information when E is displayed here.

The rightmost field always shows an estimate of the remaining battery capacity.

5.5 Application Setup Screens

There are three different screens used by the Application Setup function: Setup Selection List; Setup Parameter List; and PC Scope Screen Format. Most users will only need to be familiar with the Setup Selection List in order to choose the proper setup when changing to a new measurement application. The Setup Parameter List and PC Scope Screen Format are only used when custom setups are required for special applications.

5.5.1 Application Setup List

The Application Setup List is the initial screen shown when [RECALL SETUP] is pressed. The Measurement Setup List screen format is shown below:

The highlighted name on the top line identifies the function as Application Setup.

The middle portion of the screen is a partial list of all the available Setup names. The highlighted item identifies the selected setup. The selection highlight may be moved and the list may be scrolled to show all names by using the [ ] and [ ] keys.

The first field of the bottom status line shows when the [2nd F] key has been pressed. The second field shows the primary available keys. The third field shows E when an error occurs. The rightmost field shows the battery capacity remaining.

APPLICATION SETUP SELECTION LIST

Function name

Available keys Battery monitor

Name of Active, i.e. current Setup

List of Setups: selected Setup highlightedMODEL 25HPV 5-5

February 2004 910-215B5.5.2 Setup Parameter List

When a particular setup from the list above is selected for viewing, a list of parameter values is displayed. The Setup Parameter List screen format is shown below:

The highlighted name on the top line identifies the function as Application Setup.

The middle portion of the screen is a partial list of the parameter names and values for the selected setup. The highlighted item identifies the selected parameter, which may be moved. The [ ] and [ ] keys allow the user to scroll through all the parameters in the list. In addition, the [ ] and [ ] keys can change the setup parameter values.

The first field of the bottom status line shows when the [2nd F] key has been pressed. The second field shows the primary available keys. The third field shows E when an error occurs. The rightmost field shows the battery capacity remaining.

5.5.3 PC Scope Screen Format

The PC Scope Screen Format is used in conjunction with the optional PC Scope, which allows echo waveforms and detection markers to be shown on a personal computer while measurements are simultaneously taken and parameters changed. This function is only required when creating custom measurement setups for special measurement requirements. The PC Scope Measurement Screen format is shown below:

SETUP PARAMETER LIST

Partial list of Parameter values with selection highlighted

Battery capacity remaining

Available keys

Function name

Keyboard 2ND FunctionError

E2ND F5-6 MODEL 25HPV

910-215B February 2004The highlighted area of the first status line identifies the function as PC Scope. The second field indicates that measurements are being made and which detection method is being used. The rightmost field shows LOS prompt when there is loss of signal.

The second status line shows the name of the selected parameter and its value. Change parameter names by using the [ ] and [ ] keys, and change parameter values by using the [ ] and [ ] keys.

The middle portion of the screen shows the measured velocity/thickness value in large digits.

The first field of the bottom status line shows when the [2nd F] key has been pressed. The second field shows the primary available keys. The third field is not used. The fourth field shows E when an error occurs. The rightmost field shows the battery capacity remaining.

5.6 View/Set Screen

The purpose of the View/Set screen is to review and/or change the current value of the following gage parameters:

Differential Measurement Reference (see Section 4.6) Alarm Setpoints (see Section 4.1)

Refer to the figure below for the following discussion of the format of this screen:

MEAS 1MEAS 2MEAS 3

MEAS1

Measured Velocity/Thickness ValueMODEL 25HPV 5-7

February 2004 910-215BThe top status line indicates the view/set function name.

The middle area of the screen shows the value being viewed or changed in large numerals.

The first field of the bottom status line shows when the [2nd F] key has been pressed. The second field shows the primary available keys. On the Alarm Set Point screen, the third field shows either LOW or HIGH to indicate which Alarm Setpoint is being displayed. The fourth field shows E when an error occurs. The rightmost field shows the battery capacity remaining.

5.7 Special Mode Screens

There are two screens used by the Special Mode function: special mode names, which offers gage function selections; and a parameter or function screen that list parameters that can be changed or functions that can be performed. Refer to the image below:5-8 MODEL 25HPV

910-215B February 20045.7.1 Special Mode Selection Screen

Enter the Special Mode Selection Screen by pressing [2nd F], [IN/MM] (SP MODE). The top line of the screen identifies this mode as SPECIAL MODE SELECT.

The central area shows a list of the Special Function names. Select a highlighted name by pressing [ENTER], or move the highlighted item to another name using the [ ] and [ ] keys. The first field of the bottom status line shows when the [2nd F] key has been pressed. The second field shows the primary available keys. The third field shows E when an error occurs. The rightmost field shows the battery capacity remaining.

5.7.2 Parameter or Function Screen

Select a name from the Special Mode Selection screen to enter the Parameter or Function Screen.

SP-1 GAGE TESTS

SP-2 GAGE SETUP

SP-3 GAGE RESETS

List of Special modesMODEL 25HPV 5-9

February 2004 910-215BThe top line of the screen gives the name of the special function whose parameters or functions are displayed below.

The central area shows a list of functions or changeable parameters for the selected Special Function. Use the [ ] and [ ] keys to highlight various menus, and press [ENTER] to select the highlighted item. Use the [ ] or [ ] keys to change a highlighted parameter.

The first field of the bottom status line shows when the [2nd F] key has been pressed. The second field shows the primary available keys. The third field shows E when an error occurs. The rightmost field shows the battery capacity remaining.

5.8 Status Screen

The Status Screen briefly summarizes the gage setup such as: Current Application Setup, Current Transducer Type, and Software Version Number.

1. To review the Status Screen, press [2nd F], [REF VALUE] (STATUS).2. To return to the Measure mode, press [MEAS].

5.9 Error Help Screen

Whenever the gage detects an operational error, the character E is displayed on the fourth status line just to the left of the battery capacity value. The error condition is also signaled by an extra long duration beep.

The problem may be identified by pressing [2nd F], [REF VALUE] (STATUS) while the E is displayed. An Error Help Screen that explains the problem will be shown.

Press [MEAS] to return to the Measure mode where corrective action may be taken if necessary.

SPECIAL MODE PARAMETER OR FUNCTION SCREEN

Function name

Parameter or function list

Keyboard 2ND Function

Battery capacity remaining

Available keys Error

E2ND F5-10 MODEL 25HPV

910-215B February 20046 TECHNICAL SPECIFICATIONS

6.1 Measurement Mode

PERFORMANCE

Material Velocity Range 02000 in/S to .66929 in/S(0.5080mm/S to 17.0000mm/S)

Thickness Range Thickness measurements fall within a range depending on the setup, material, and transducer. Detailed ranges for each standard setup are specified in Table 6-1 in Section 6.3Application Setups.

In general, selecting the proper setup allows velocity measurements for the following ranges:Steel: 0.050" to 25.000"

(1.25mm to 635.00mm)Plastic: 0.020" to 2.000"

0.50mm to 50.00mm)

Material Velocity Resolution .0001 in/S (.001mm/S)

Zero Cal Range 0.00 to 999.99 zero counts

Measurement Display Update Rate

Keypad selectable: 1, 2, 5, 10 measurements per second, averaging, or averaging with Quality Bar. Averaging is a running average of 5 measurements at a 10/sec update rate.

Differential Reference Range 0.0 to 25.000 in (635.00mm)0 to .6692 in/sec (17.000mm/sec)

Differential Reference Resolution

Same as current gage resolution

Alarm Setpoints Range Velocity mode: 0.0 to .6692 in/sec(17.000mm/sec)

Thickness mode: 0.0 to 25.000 in(635.00mm)

Alarm Setpoint Resolution Same as current gage resolutionMODEL 25HPV 6-1

February 2004 910-215BFUNCTIONS

6.2 Application Setups

Application Setups are a set of stored configurations of the gage parameters for various measurement applications. Setups are optimized for such application features as material, thickness range, and required accuracy or resolution.

When the gage is turned on, the last Setup used is automatically selected and the gage is ready to make similar measurements.

If the application has changed, choose an Application Setup name based on the new application (refer to Table 6-1).

Units The measurement units are keypad selectable as either inches or millimeters.

Resolution If fixed at 00.001 in (00.01mm) Thickness mode, and 0.0001in/sec (00.001mm/sec) Velocity mode

Echo Detection Methods The following are selected as part of the Application Setup. (See Section 6.2Application Setups.)

Mode 1: Time between excitation pulse and first echo following blank period using contact transducers.

Mode 2: Time between the interface echo and the first backwall echo. Normally used with delay line or immersion transducers.

Mode 3: Time between a pair of backwall echos following the interface echo. Normally used with delay line or immersion transducers.

Hold/blank The velocity/thickness display during LOS may be set to either HOLD the last reading during LOS or BLANK the display during LOS.

Differential The velocity/thickness display may be set to display either actual measured velocity/thickness or the difference between the measured velocity and a user-set Differential Velocity/Thickness Reference Value. The default is a Diff. Ref. Value of 0.000 and Diff Measure mode OFF.

Alarm The gage may be set to indicate visually and audibly whenever the measured velocity/thickness is less than a user-set Low Alarm value or greater than a user-set High Alarm value.The default is Low Alarm value = 0.000, High Alarm value = full scale, and Alarm Measure mode OFF6-2 MODEL 25HPV

910-215B February 2004Note: A transducer of the type specified for the selected setup should be plugged into the gage.

Table 6-1: Application Setup Name and Application

Setup Name Probe Type Typical Application

DEF-M106 M106Very coarse grained and/or rough surfaced metals up to 20" or 508mmDEF-M109 M109

DEF-M110 M110 Grainy and/or rough surfaced metals up to 10" or 250mm

DEF-M1036 M1036 Grainy and/or rough surfaced metals up to 20" or 508mm

DEF-M2008 M2008 Fiberglass up to 3" or 75mm

Note: The maximum thickness measuring capability depends on the attenuation characteristics of the material.MODEL 25HPV 6-3

February 2004 910-215BTable 6-2: Thickness Ranges

Probe Type Thickness Range for Steel Thickness Range for LDPE

M101 0.5"-20" 12mm-508mm 0.2"-5" 5mm-125mm

M102 0.2"-20" 5mm-508mm 0.1"-3" 2.5mm-75mm

M103 0.1"-20" 2.5mm-508mm 0.075"-3" 2mm-75mm

M106 0.075"-20" 2mm-508mm 0.050"-3" 1.2mm-75mm

M1036 0.075"-20" 2mm-508mm 0.050"-5" 1.2mm-125mm

M109 0.050"-20" 1.2mm-508mm 0.040"-2" 1.0mm-50mm

M110 0.050"-10" 1.2mm-250mm 0.040"-1" 1.0mm-25mm

M201 0.050"-0.5" 1.2mm-25mm 0.040"-0.5" 1.0mm-12mm

M206 0.050"-1.0" 1.2mm-25mm 0.040"-0.5" 1.0mm-12mm

M207 0.100"-1.0" 2.5mm-25mm 0.075"-0.5" 2.0mm-12mm

M2008 High density/smooth fiberglass:0.2"-3" 5.0mm-75mm

Woven roving/rough surfaced fiberglass:0.2"-1" 5.0mm-25mm

Note: The maximum thickness measuring capability depends on the attenuation characteristics of the material.

Setup Quantity There are 5 factory default setups and space for 5 custom or user defined setups

Custom Application Setups Applications that are not covered by any of the default setups can be measured by creating a custom setup for the special application. This setup may be done by adjusting the parameters of the closest default setup.

A description of the setup parameters, which can be adjusted to make a custom setup, is listed in Table 6-3 below:6-4 MODEL 25HPV

910-215B February 2004.

Table 6-3: Setup Parameter Description

Name Description Units/Resolutions/Range

ProbeType Transducer type One of the many Panametrics-NDTTM transducer types from the setup list.

MatlVel Ultrasonic sound velocity of material to be measured

.02000 - .66929"/s (0.5080 - 17.0000mm/s)

Zero Zero calibration factor 0 -999.99

PulserPwr Pulser power 30, 60, or 110 Volts

MaxGain Maximum receiver gain 0 - 79.6dB, 1dB steps

InitGain Initial T.V.G. gain 0 - MaxGain, 1dB steps

TVGSlope Time Varied Gain slope 0 - 26.5dB/s, 0.1dB/s steps

MBBlank Main Bang Blank 55ns to 200s, 0.14s steps. 22ns or Echo Window time interval, whichever is less

EchWindow Echo window. Echo detect gate which begins at end of MB Blank in mode 1 or interface echo in modes 2 & 3. The value reported for the end of Echo Window is relative to the Main Bang.

55ns to 200s, .014 s steps. 55ns or MB Blank time interval, whichever is less

DtectMode Echo Detect Mode 1, 2 or 3

Ech1Dtect Detection polarity of first echo + or -

Ech2Dtect Detection polarity of second echo + or -

I/FBLANK Blank after Interface echo 0 -20000 ns, 14 ns steps

M3EchBlnk Blank after first measured backwall echo in mode 3

0 - 20000 ns, 14 ns stepsMODEL 25HPV 6-5

February 2004 910-215B6.3 General

.

6.4 Battery and Charger

Display Dot matrix, graphics, Super Twisted Nematic, monochrome, transflective, liquid crystal display

Viewable area is 2.22" x 1.51" (56.28mm x 38.36mm). Electroluminescent backlight. Contrast is adjustable from the keypad.

Keypad Sealed and embossed membrane surface. Tactile and audible feedback color-coded graphics 15 keys.

Tranducers Can be used with contact, delay line, and immersion transducers from 0.5MHz to 5.0MHz. Default setups are provided for the five (5) Panametrics-NDTTM probes listed in Section 6.3Application Setups and Table 6-2 in this section.

Physical Size: 7.70" x 3.39" x 1.70"(195.6mm x 86.2mm x 66.9mm)

Weight: 1.3 lb. (0.59 kg)Case: Material is LexanConstruction: Dust and splash proofOperating Temperature: 0C to 50C

Battery Description Nickel Cadmium, rechargeable, rated 6 Volts at 700 mAHr

Battery Run Time 30 hours typical, 10 hours with backlight on continuously

Battery Charge Time 7 hours (using 26CA PLUS)

Charger External wall plug-in charger for 100VAC, 115VAC, and 230VAC inputs (Panametrics-NDTTM Part # 26CA PLUS)

Optional Operation with four (4) disposable alkaline AA cell is available as a factory installed option, 70 hours typical run time.6-6 MODEL 25HPV

910-215B February 20046.5 Special Gage Functions

General Access many gage functions, which do not require frequent changing, by using the Special or SP keypad mode.

These features may all be accessed by pressing [2ND F], [IN/MM] (SP MODE). Then use [ ], [ ], and [ENTER] to select a category of SP functions (SP-1 thru SP-3). Finally a particular function may be selected and modified by using [ ], [ ], [ ], [ ], and [ENTER].

List of Special Functions SP-1 Gage TestsDisplay TestKeyboard TestHardware Test

SP-2 Gage SetupInactive Time: off, 6*, 12, 18Beeper: on* or offLanguage: English, French, German, SpanishDecimal Point: period* or commaHold/Blank: Blank* or HoldCal Lock: on or off** Indicates the features default value.

SP-3 ResetsMeasure Reset: Std. resolution, 2/sec measure rate,

0.000 diff. value, diff mode OFF, 0.000 low alarm setpoint, full scale high alarm setpoint, alarms OFF, min OFF, max OFF, BLANK on LOS, Cal lock OFF, default contrast, auto shutdown on, auto shutdown 6 minutes, backlight OFF, low velocity resolution

Master Reset: Resets ALL parametersMODEL 25HPV 6-7

910-215B February 20047 BATTERY

An internal 6V battery pack using rechargeable Nickel Cadmium (NiCd) batteries powers the Model 25HPV. Panametrics-NDTTM supplies the gage with the Model 26CA PLUS Charger/AC Adapter battery pack. Other chargers may reduce battery life and will void the gages warranty.

7.1 Low Battery

The gage operates for at least 20 hours between charges under normal conditions (excluding High Measure Rates, or activated backlight). The screen always displays the current battery status in the lower right corner using an indicator to show the remaining battery life with a maximum indication of 99%.

7.2 Charging Batteries

The batteries are fully charged when shipped, but to ensure the longest operating time they should be recharged before using. To charge the batteries, simply plug the cable from charger into the socket on the top of the gage. Normal charging time for a completely discharged battery is about 8 hours. When the remaining charge drops to about 1% of a full charge, the gage automatically shuts off. If the battery is insufficiently charged, then the gage will automatically turn off to prevent damage to the battery.

Caution: Charging batteries for more than 16 hours at a time may reduce battery life.

During charging, the gage can be operated in the usual way with little effect on charging time. However, the battery status indicator is not valid when the charger is plugged in and cannot be used to determine the remaining charge time.

Even an uncharged battery will maintain the stored calibration values and velocity data for several weeks. Moreover, the gage has an internal back-up battery to maintain data in memory even when the main battery is completely removed. This internal battery, with the main battery installed, lasts five to seven years during normal use of the gage and does not require recharging. However, to preserve the life of both batteries, it is not recommended to leave the gage without a battery, or with an uncharged main battery for long periods of time. Please note that the backup battery does not have a status indicator.MODEL 25HPV 7-1

February 2004 910-215B7.3 Changing Battery Pack

After several hundred recharges, the batteries lose their ability to hold a full charge and require replacement. Follow the steps below to change the battery pack:

1. Access the battery compartment through the back cover of the gage.

2. Remove the cover by loosening the captive screw.

3. Extract the battery by gently unplugging the old battery.

4. Plug in and install a new battery.

5. Replace the back cover and tighten the captive screw in place.

As mentioned before, the content of the internal memory, which includes velocity and zero calibration data will be preserved by the back-up battery. The total back-up time is around 5000 hours and every time the gage is left without the main battery, part of this total time is deducted.

7.4 Optional Battery Pack

Non-rechargeable alkaline batteries are available as a factory installed option. The operating time for these batteries is about 2-3 times longer than NiCd batteries. However, primary batteries normally cannot be charged. Therefore the gage, equipped with alkaline batteries, cannot use the charger-AC adapter and consequently cannot be operated from an AC main line even if the alkaline batteries are removed or replaced by NiCd batteries.7-2 MODEL 25HPV

910-215B February 20048 THEORY OF OPERATION

The Panametrics-NDTTM Model 25HPV Ultrasonic Velocity/Thickness Gage operates on the Pulse/Echo principle. This principle works by precisely timing the reflection of high frequency sound waves from the transducer to the far wall of a test piece. This technique, derived from sonar, has been widely applied to nondestructive testing because it permits accurate measurement of material velocity/thickness even though only one side may be accessable.

The Model 25HPV uses a variety of piezoelectric transducers that generate bursts of mechanical vibrations, or sound waves, when excited by short electrical pulses. The frequency of these sound waves is far beyond the limit of human hearing; from one million to 20 million cycles per second, versus a typical limit of less than 20 thousand cycles per second for the human ear. Sound at these very high frequencies does not travel well through air, so a coupling medium such as a drop of liquid (usually propylene glycol, glycerin, water, or oil) is used between the transducer and the test piece.

The sound waves, generated by the transducer coupled to the test piece, reflect back from the opposite side of the test piece. The same transducer then receives the reflected sound waves and converts them into electrical pulses. The gage amplifies the received signal, digitizes a selected portion of the wavetrain, and then very precisely measures a time interval corresponding to one round trip of the sound waves in the test piece. This measurement is made in one of three modes as described below.

The gage, when in the Velocity Measurement mode and calibrated to the Zero Offset of the transducer, computes the velocity of the test material using the relationship:

where V = the velocity of sound in the material

t = the measured round-trip transit time of the pulse

t0 = the zero offset factor (to correct for transducer wearplate delay, cable delay, and other fixed delays)

Ref Value = User set mechanical thickness at measurement location

V 2 Ref Value( )t t0

----------------------------------=MODEL 25HPV 8-1

February 2004 910-215BThe gage, when in Thickness Measurment mode and calibrated to the Zero Offset of the transducer and velocity of the material, computes the thickness of the test material using the relationship:

where x = the thickness of the material

V = the velocity of sound in the material

t = the measured round-trip transit time of the pulse

t0 = the zero offset factor (to correct for transducer wearplate delay, cable delay, and other fixed delays)

The Model 25HPV can employ any of three (3) measurement modes to calculate pulse transit time. The selection of the proper mode for a given application is dependent on a number of factors discussed in detail in Chapter 9Application Notes.

Mode 1 is utilized with contact transducers. In this mode, the measurement is made from the initial excitation pulse to the first returning echo from the backwall of the test piece. The MTI marker indicates the Measured Time Interval.

Mode 2 is utilized with delay line and immersion transducers. In this mode, the measurement is made between an interface echo marking the time the sound wave enters the test piece and the first backwall echo. The MTI marker indicates the Measured Time Interval.

Mode 3 is also utilized with delay line and immersion transducers. In this mode, the measurement is made between two successive backwall echoes that follow an interface echo. The MTI Marker indicates the Measured Time Interval.

xV t t0( )

2---------------------=8-2 MODEL 25HPV

910-215B February 2004Figure 8-1 is a block diagram of the Model 25HPV. The pulser, under the control of the microprocessor, provides a unidirectional broadband spike voltage impulse to a heavily damped broadband ultrasonic transducer. The broadband ultrasonic pulse generated by the transducer is coupled to the test piece by means of liquid couplant. Echoes returning from the back or inside surface of the test piece are received by the transducer and converted to electrical signals, which in turn are fed to the receiver AGC amplifier. The microprocessor-based control and timing logic circuits both synchronize the pulser and select the appropriate echo signals that will be used for the time interval measurement.

Figure 8.1: Model 25HPV Block Diagram

Battery PowerSupplyROM RAM

Detector

LCD

Keyboard

Transducer Charger RS-232 Output

Control and MeasurePulser AGCAmplifierMODEL 25HPV 8-3

February 2004 910-215BIf echoes are not detected during a given measurement period, the gage will shut down to save power until a new measurement cycle is required. If echoes are detected, the timing circuit will precisely measure an interval appropriate for the selected measurement mode, and then repeat this process a number of times to obtain a stable, averaged reading. The microprocessor then uses this time interval measurement, along with sound velocity and zero offset information stored in the Random Access Memory (RAM), to calculate velocity. Finally, the velocity is shown on the Liquid Crystal Display (LCD) and updated at a selected rate.8-4 MODEL 25HPV

910-215B February 20049 APPLICATIONS NOTES

The Model 25HPV Ultrasonic Velocity/Thickness Gage is a versatile and easy to use instrument that provides precise, repeatable velocity readings in a wide variety of applications when proper technique is employed. This section discusses advanced gage usability and measurement techniques to assist in challenging applications.

To take maximum advantage of the gages versatility, the user should be familiar with the basic principles of ultrasonic nondestructive testing. There are several textbooks that discuss this subject in detail, as well as classroom training opportunities. Consult Panametrics-NDTTM for further information.

9.1 Measurement Mode

The Model 25HPV is capable of operating in three measurement modes, representing three alternate ways of timing echoes. Mode selection is usually based on the requirements of a particular application as described below:

Mode 1: Measurements are made between an excitation pulse and the first backwall echo from the test piece, using contact-type transducers. Mode 1 is a general purpose test mode, and is normally recommended for use, unless one of the conditions described under Modes 2 or 3 is present. A modified version of Mode 1 is used with the M2008 transducer only.

Mode 2: Measurements are made between an interface echo representing the near surface of the test piece and the first backwall echo, using delay line or immersion transducers. Mode 2 is most often used for high-temperature measurements with high-temperature delay line transducers; measurements on sharp concave or convex radiuses; in confined spaces with delay line or immersion transducers; and for on-line measurement of moving material with immersion transducers.

Mode 3: Measurements are made between two successive backwall echoes, using delay line or immersion transducers. This mode may be employed only when clean multiple backwall echoes appear, which typically limits its use to materials of relatively low attenuation and high acoustic impedance such as fine-grained metals, glass, and ceramics. Mode 3 typically offers the highest measurement accuracy and the best minimum thickness resolution in a given application, at the expense of penetration, and it is used when accuracy and/or resolution requirements cannot be met in Mode 1 or Mode 2.

Ultrasonic velocity/thickness measurements utilizing contact transducers in Mode 1 are generally the simplest to implement and may be used in the majority of applications. For most materials the contact method of measurement provides the highest coupling efficiency of ultrasound from the transducer into the test piece. Mode 1 contact measurements can generally be used with the Model 25HPV when minimum material thickness does not fall below approximately 0.025" (0.6mm) of plastic or 0.050" (1.25mm) of metal, test material is at room temperature, and geometry permits contact coupling. Mode 2 and Mode 3 measurements with delay line and immersion transducers are, as noted above, generally recommended when application requirements preclude use of Mode 1. The M2008 transducer uses a modified Mode 1 measurement.MODEL 25HPV 9-1

February 2004 910-215B9.2 Transducer Selection

The selection of the appropriate transducer for a given application is based on the range and resolution of the thickness measurement required, the acoustic properties of the test material, and part geometry. Choose the best mode by experimenting with test standards representing the desired range of measurement. Generally, the highest frequency and smallest diameter transducers that give acceptable results over the required range is recommended. Small diameter transducers are easily coupled to test material and permit the thinnest couplant layer at a given contact pressure. Furthermore, higher frequency transducers produce echo signals of faster rise time and thereby enhance the precision of velocity measurements. On the other hand, the acoustic properties or surface condition of the test material may require larger, low frequency transducers to overcome poor coupling or signal losses due to scattering or attenuation.

The Model 25HPV is programmed with five (5) different internal setups for use with a wide variety of transducers. Five (5) additional custom setups may be created for special applications not measurable by any of the standard internal setups. In some applications, optimum performance will entail the use of more than one transducer. Table 6-1, in Section 6-3, lists some common transducers and typical measurement ranges. For further information on specific transducer recommendations, consult Panametrics-NDTTM.

Note: For best results, only recommended Panametrics-NDT transducers should be used with the Model 25HPV, insuring suitable electrical impedance, bandwidth, sensitivity, and Main Bang recovery characteristics. While the gage may work with transducers from other manufacturers, Panametrics-NDT cannot guarantee performance. Additionally, transducers must be maintained in good condition. Broken or cracked wearplates, worn delay lines, and thermal damage will all degrade performance and affect measurements.

9.3 Factors Affecting Performance and Accuracy

1. Calibration: The accuracy of any ultrasonic measurement is only as good as the accuracy and care with which the gage has been calibrated. The Model 25HPV is shipped from the factory with standard setups for a number of transducers and applications. In some cases it will be desirable to optimize these setups for specific measurement situations, as described in Section 3. In all cases, it is essential that the Cal Thick and Cal Thin, also described in Section 3, are performed whenever the transducer is changed. Periodic checks with samples of known velocity are recommended to verify that the gage is operating properly.

2. Surface Roughness of the Test Piece: The best measurement accuracy is obtained when both the front and back surfaces of the test piece are smooth. If the contact surface is rough, then the minimum thickness that can be measured will be increased because of sound reverberating in the increased thickness of the couplant layer. Additionally, if either test piece surface is rough it may cause distortion in the returning echo due to the slightly different multiple sound paths seen by the transducer, resulting in measurement inaccuracies. 9-2 MODEL 25HPV

910-215B February 20043. Coupling Technique: In Mode 1 (contact transducer) measurements, the couplant layer thickness is part of the measurement and is compensated by a portion of the zero offset. If maximum accuracy is to be achieved, then the coupling technique must be consistent. In order to accomplish consistent measurements, use a couplant of reasonably low viscosity; employ only enough couplant to achieve a reasonable reading; and apply the transducer with uniform pressure. A little practice will show the degree of moderate to firm pressure that produces repeatable readings. In general, smaller diameter transducers require less coupling force to squeeze out the excess couplant than larger diameter transducers.

In all modes, tilting the transducer distorts echoes and causes inaccurate readings, as noted below.

4. Curvature of the Test Piece: A related issue to this section involves the alignment of the transducer with respect to the test piece. When measuring on curved surfaces, it is important that the transducer be placed approximately on the centerline of the part and held as steadily to the surface as possible. In some cases a spring-loaded V-block holder may be helpful for maintaining this alignment. In general, as the radius of curvature decreases, the size of the transducer should be reduced, and the more critical transducer alignment will become. For very small radii, an immersion approach will be necessary. In some cases it may be useful to observe the waveform display via the PC Scope option as an aid in maintaining optimum alignment. Practice the best way to hold a transducer with the aid of a waveform display.

On curved surfaces it is important to use only enough couplant to obtain a reading. Excess couplant will form a fillet between the transducer and the test surface where sound will reverberate and possibly create spurious signals that may trigger false readings.

5. Taper or eccentricity: If the contact surface or back surface of the test piece is tapered or eccentric with respect to the other, the return echo will be distorted due to the variation in sound path across the width of the beam. Accuracy of measurement will be reduced. In severe cases no measurement will be possible.

6. Acoustic Properties of the Test Material: There are several conditions found in certain engineering materials that can potentially limit the accuracy and range of ultrasonic velocity measurements:

a. Sound Scattering: In materials such as cast stainless steel, cast iron, fiberglass, and composites, sound energy will scatter from individual crystallites in the casting or boundaries of dissimilar materials within the fiberglass or composite. Porosity in any material can have the same effect. Gage sensitivity must be adjusted to prevent detection of these spurious scatter echoes. This compensation can in turn limit the ability to discriminate a valid return echo from the backside of the material, thereby restricting measurement range.

b. Sound Attenuation or Absorption: In ma