DATAPLATE Digital Hot Plate/Stirrer · The DATAPLATE Hot Plate/Stirrer Series 730 is a programmable, general purpose, digital laboratory hot plate with stirrer. The series includes

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DATAPLATE®

Digital Hot Plate/Stirrer

OPERATING MANUAL

SERIES 730

730-0024 4/22/96

BARNSTEAD|THERMOLYNE CORPORATION

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Table of Contents

Introduction ........................................................................................................................................... 3Warnings ............................................................................................................................................... 5Cautions ................................................................................................................................................ 6General Description .............................................................................................................................. 8Other Instruments in the 700 Series ................................................................................................... 12Non-Programmed Operation ............................................................................................................... 14

Front and Rear Panels .................................................................................................................... 14Operating Instructions ..................................................................................................................... 17Display Functions ........................................................................................................................... 18Setting Temperature, Ramp Rate, Stir Speed & Timer .................................................................. 20Auto-Off Function ............................................................................................................................ 26Other Modes of Operation .............................................................................................................. 27

Programmed Operation....................................................................................................................... 30Front Panel Controls ....................................................................................................................... 30Editing a Program ........................................................................................................................... 31Running a Program......................................................................................................................... 34Example Program ........................................................................................................................... 36Modifying a Program....................................................................................................................... 40

Maintenance........................................................................................................................................ 41Temperature Calibration ................................................................................................................. 41Helpful Hints ................................................................................................................................... 43Battery Replacement ...................................................................................................................... 44

Troubleshooting .................................................................................................................................. 46

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Introduction

Congratulations on your purchase of a DigitalHot Plate/Stirrer.

Introduction

The unit is designed to do a number of jobswithin your laboratory. Please read theinstructions carefully to insure that you receivethe maximum benefit from it. Also, be sure to fillout and return the enclosed warranty registrationcard. We would like to receive the informationrequested, and it will help us assure you ofproper warranty coverage.

Important Information

This manual contains important operating andsafety information. You must carefully read andunderstand the contents of this manual prior tousing this equipment.

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INTRODUCTION

Safety Information

Your Dataplate Digital Hot Plate/Stirrer has beendesigned with function, reliability, and safety inmind. It is the user's responsibility to install it inconformance with local electrical codes. For safeoperation, please pay attention to the alert boxesthroughout the manual.

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Please note the following WARNINGS:

WARNINGTHIS PRODUCT CONTAINS REFRACTORY CERAMIC, REFRACTORY CERAMIC FIBEROR FIBERGLASS (GLASS WOOL) INSULATION WHICH CAN PRODUCE RESPIRABLEFIBERS AND DUST WHEN HANDLED. THESE FIBERS OR DUSTS CAN CAUSEIRRITATION AND CAN AGGRAVATE PRE-EXISTING RESPIRATORY DISEASE.REFRACTORY CERAMIC INSULATIONS MAY CONTAIN OR MAY FORMCRYSTALLINE SILICA (CRYSTOBALITE) WHICH MAY CAUSE LUNG DAMAGE(SILICOSIS).

THE INTERNATIONAL AGENCY FOR RESEARCH ON CANCER (IARC) HASCLASSIFIED REFRACTORY CERAMIC FIBER AND FIBERGLASS AS (2B) POSSIBLYCARCINOGENIC. IARC HAS CLASSIFIED CRYSTALLINE SILICA AS (2A) PROBABLYCARCINOGENIC.

The insulating materials are located in the door, the hearth collar, in the chamber of theproduct or the top plate assembly. Tests performed by the manufacturer indicate that thereis no significant risk of exposure to dust or respirable fibers resulting from operation of thisequipment under normal conditions. However, there may be a risk of exposure to respirabledusts or fibers when repairing or maintaining the insulating materials, or when otherwisedisturbing the materials in a manner which causes release of dust or fibers therefrom.Through the use of proper handling procedures you can work safely with these insulatingmaterials and minimize any exposure. Accordingly, before you repair or replace anyinsulating materials, or perform any other servicing on this product which could disturb orcause exposure to dust from insulating materials, you should consult the appropriateMaterial Safety Data Sheets (MSDS’s) for such products with respect to proper handling andappropriate protective equipment. For additional MSDS’s, or additional informationconcerning the handling of refractory ceramic products, please contact the CustomerService Department of Barnstead|Thermolyne Corporation.

WARNINGREFER SERVICING TO QUALIFIED PERSONNEL.

1-800-553-0039

Warnings

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Cautions

Heater Plate Surface

DATAPLATE Hot Plate/Stirrer Series 730 iscapable of temperatures in excess of 370°C, ±tolerance, at the plate surface. Touching theheated surface will cause severe burns. USEEXTREME CAUTION AT ALL TIMES. Neverleave your DATAPLATE Hot Plate/Stirreraccessible to others while it is hot. Although theunit is equipped with a "Hot Warning" indicator onthe front panel, do not rely on this alone. Nevertouch the heating surface unless you areabsolutely sure that it is cool.

Temperature Probe

When attempting to control PROBETEMPERATURE, it is necessary to plug in atemperature probe and to place it in the sampleAT ALL TIMES. If the probe is not placed into thesample, the unit will not be able to sense therising temperature of the sample as heat isapplied. This will result in driving the heater to itsmaximum and could result in ruining the sample.

Caution

Touching the heated surfacewill cause severe burns. USEEXTREME CAUTION AT ALLTIMES.

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The optional temperature probe is made of 316stainless steel and can be attacked by somechemicals. Coating the probe with Teflon sprayor Teflon tubing may help. However, this coatingmay slow the probe response time and result intemperature errors until it equilibrates. Alsoavailable is our borosilicate glass temperatureprobe #710-0203 for use with very aggressivechemicals.

Electrical

The DATAPLATE Hot Plate/Stirrer 730 Series ismade in models that operate at 100, 120 and240 volts AC. Be certain that your voltagematches the unit that you receive. Check theplate on the bottom for the voltage setting onyour unit. Take the normal care and precautionone would use with any electrical appliance. Bevery careful to keep the AC line cord away fromthe hot plate.

CAUTIONS

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The DATAPLATE Hot Plate/Stirrer Series 730 isa programmable, general purpose, digitallaboratory hot plate with stirrer. The seriesincludes the Model 731 single position stirrer theModel 735, 5-position stirrer and the Model 739,9-position stirrer. All functions on the Series 730are settable from a digital front panel keyboardand display. Both the plate temperature and thestirrer speed are controllable to an accuracynever before offered in similar devices.

The Series 730 contains a program memory of75 steps. The user may enter a sequence ortemperature, stir speeds and time delays whichmay then run by pressing a single button. Theprogram memory is battery-powered so theprogram remains in the unit indefinitely when it isturned off.

The 730 Series also has an infraredremote control sensor circuit. The optional Model475 remote control keyboard can be used tooperate the various models from distances of upto 15 feet. This typically is used in situationswhere the unit is kept under a fume hood or isotherwise inaccessible.

General Description

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Heater

Either the plate surface temperature or the actualsample temperature may be set by the user. Asensor in the plate is used to monitor surfacetemperature or alternatively a temperature probemay be connected to the rear of the unit andinserted into the sample. An optional 100Ω 3-wirePlatinum RTD temperature probe is availablewith a 6" stainless steel or glass jacket. When atemperature is set by the user, power is appliedto the heater to precisely control the temperatureat the plate surface or at the sample, as directed.

An optional "ramp value" may be entered intothe unit which causes the temperature toapproach the target value at a controlled rate oftemperature change. The unit may also beprogrammed to follow any temperature vs timeprofile which the user desires so long as theprogram does not exceed 75 steps. Temperaturemay be displayed in either °C or °F as set by arear panel switch.

GENERAL DESCRIPTION

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Stirrer

The stirrer is a motor-driven magnet which, in themodel 731, revolves directly under the center ofthe heater plate. The Model 731 has five motorswith one placed in the center and one at eachcorner of the plate. The Model 739 has ninestirrer motors placed in three rows of three each.It is common practice, when heating solutions, tospin a "stir bar" (Teflon-coated bar magnet)which is placed in the solution. This assures amore uniform temperature throughout thesolution.

The stirrer speed is set from the front panelkeyboard and may be one of the variables inprogrammed operation.

GENERAL DESCRIPTION

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Timer

All Series 730 units have built-in timers. Thetimer counts down in hours, minutes andseconds, sounding an alarm when it reacheszero. The timer may be used independently ofthe heater and stirrer or may be used inconjunction with the "Auto Off" function to shut offboth the heater and stirrer after a preset length oftime.

GENERAL DESCRIPTION

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Other Instruments

Barnstead|Thermolyne manufactures a full line ofDATAPLATE Hot Plate/Stirrers and accessories.Some of the other products in this line aredescribed below.

Series 720 Digital Hot Plate/Stirrer

The Series 720, available in 1,5, and 9 positionstirrer models, is a general purpose, digitallaboratory hot plate/stirrer. The 720 Series has allof the features of the 730 Series with theexception of the programmed operation and theremote infrared sensor.

Model 740 Multi-Controller

Both Series 720 and 730 DATAPLATE Hot Plate/Stirrers may be operated as remote stations tothe Model 740 DATAPLATE Multi-Controller.The Multi-Controller connects to the units througha small cable, and is capable of controlling up to8 units at a time. The Multi-Controller provides a

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number of enhancements, including 0.1 degreetemperature resolution, larger program memory,real-time clock and printer interface.

When connected to the Multi-Controller, frontpanel controls on both Series 720 and 730 HotPlate/Stirrers remain operational. Also availablefor use with the Model 740 Multi-Controller is theSeries 710 Hot Plate/ Stirrer which is the sameunit as the Series 720 but has no front panelcontrols. It is designed to be operated remotelyfrom the Model 740 Multi-controller.

OTHER INSTRUMENTS

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Front And Rear Panels

Front PanelThe front panel of the DATAPLATE 730 Serieshas a digital keyboard display for monitoring andcontrolling hot plate functions. The ON/Off switchis located on the right side of the front panel.When the unit is on, the display located on theleft side of the unit will be lighted.

The display is a four-digit vacuum fluorescenttype with a colon between the middle two digits. Itis used to display the temperature, stirrer speedand timer value. The keyboard has 12pushbutton keys and is used both for selectingthe display function and for entering numericalvalues for the temperature, stirrer speed andtimer.

A number of LED indicator lamps also arelocated on the front panel. These will beexplained in a later section.

Non-Programmed Operation

Note

Keyboard labels which referonly to programmedoperation have been omittedfrom the illustration forclarity.

Front Panel

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A thin plastic membrane which fits over the frontpanel is supplied with the unit to protect it fromdust, dirt and possible chemical spills. Thekeyboard may be operated with the membrane inplace. Replacement membranes are available.

Rear PanelThe AC power connector jack and fuse holdercombination is located on the left side of the rearpanel. The °C/°F display switch is to its right,followed by the l/O port, the remote temperaturesensor jack and the four temperature calibrationpots on the right side of the panel.

The AC power jack is a three-prong,international-style jack combined with a dual,snap-in fuse holder. The type of fuse used in theunit is shown on the rear panel. Both neutral andhigh lines are fused.

The °C/°F display is controlled by the position ofthe slide switch to the right of the power jack. Thefront panel display will reflect the temperatureunits by displaying a °C or °F after thetemperature readout.

NON-PROGRAMMED OPERATION

Rear Panel

If the fuse blows repeatedly,contact the distributor.

Caution

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The I/O port will, when used with the propercable, allow for remote control of the unit by theModel 740 multicontroller.

The remote temperature sensor input is a DINjack which is used with a three-wire, PlatinumRTD temperature probe. The probe pinoutarrangement is as follows:

Pin 1 - PositivePin 2, 3 - Negative

The two calibration potentiometers on the left arefor calibrating the remote temperature sensor,the two on the right are for calibrating the hotplate temperature readout.


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Operating Instructions

The DATAPLATE Digital Hot Plate/Stirrer issimple to use. Once you've learned, you won'twant to twist a dial or knob on another hot plate/stirrer again.

Set-Up1)Place the unit on a level, dry bench or surface.

2)Plug the unit into a properly grounded, threewire outlet of proper voltage.

3)Plug the temperature probe (if used) into thejack on the rear of the unit.

4)Place the sample on the heater plate and putthe temperature probe and stir bar into thesample. Be sure the vessel is centered and thatthe stir bar is centered in the vessel. Also be surethat the temperature probe will not obstruct therotation of the stir bar.


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Try to match the stir bar to the sample andcontainer size to optimize mixing. Generally,larger stir bars are needed to mix more viscoussamples. However, two-inch long bars match themagnet in the stirrer best.

5) Turn the unit ON by the rocker switch on thefront panel. Note that the unit will beep once andwill be in the PLATE TEMPERATURE mode. Atthis point you can change the display modes bytouching PLATE TEMP, PROBE TEMP,STIRRER RPM, TIMER HR:MIN, or TIMERMIN:SEC. Note that the display indications willchange as you touch the different keys.

6)Set the target temperature, stirrer speed, timerand ramp rate according to the instructions thatfollow.

Display Functions

The display can be instructed to show any of fivedifferent functions. The function currently beingdisplayed is indicated by a small LED lamplocated above the corresponding display functionkey (top row of keys).


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HEATER

Press this key to display the temperature of theheater plate surface. The display will be in °C or°F as selected by the rear panel C/F switch, andindicated by a "C" or "F" on the right portion ofthe display. If a target plate temperature hasbeen set into the unit, the display will toggle atbrief intervals to display the target temperature.The PLATE TARGET lamp will turn on duringthe time the target temperature is shown. The redPLATE HOT lamp located to the right and belowthe display, will blink if the plate temperature isabove 50 °C (122 °F) as a safety reminder.

Press this key to display the temperaturemeasured by the probe. The display will be in °Cor °F as selected by the rear panel C/F switchand indicated as above. If a target probetemperature has been set, the display will toggleat brief intervals to display the targettemperature. The PROBE TARGET lamp will turnon during the time that the target temperature isshown. If the probe is unplugged the display willshow all dashes (- - - -). The same display willalso appear if the temperature is out of range(0 - 400°C).


2

PROBETEMP

1

PLATETEMP

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STIRRER SPEED

Press this key to display the speed of the stirrer.The speed is shown to the nearest ten RPM. Onmulti-position stirrer models the speed is takenfrom the center stirrer position.

TIMER

Press this key to display the hours and minutesleft on the timer.

Press this key to display the minutes andseconds left on the timer.

Setting Temperature, RampRate, Stirrer Speed and Timer

The heater, stirrer and timer all may be setthrough the use of the SET/ENTER key. Thesettable functions are listed below, followed by anexplanation of how values are entered for thosefunctions.


5

TIMERMIN:SEC

4

TIMERHR:MIN

3

STIRRERRPM

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Heater

The heater may be set to control either the platesurface or the sample itself. This is done byentering a "target" temperature from the frontpanel keyboard. The control electronics in the hotplate will automatically apply power to the heaterplate to reach the desired target temperature.

The user may enter either a target platetemperature or a target probe temperature. Onlyone target temperature is allowed at a time.Setting a target plate temperature erases anytarget probe temperature that may have been setpreviously and vice versa.

Target temperatures may be set anywhere in therange of 0 to 370°C (32 to 698°F).

To set a target plate temperature, press the SETkey followed by the PLATE TEMP key; enter thetemperature value desired and press the ENTERkey. The target temperature is entered in °C or °Fdepending on the current mode as set by the C/Fswitch on the rear panel. Setting a targettemperature enables the heater plate. Thismeans that the heater plate will turn on as


1

PLATETEMP

Enter

SET

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necessary to heat the plate surface to the targettemperature. If the target is below the actual platetemperature, the heater plate will not turn on untilthe plate cools to near the target temperature.

To set a target probe temperature, press the SETkey followed by the PROBE TEMP key;enter the temperature value desired and pressthe ENTER key. The target temperature isentered in °C or °F depending on the currentmode as above. Setting the targettemperature enables the heater plate. The heaterplate will turn on as necessary to heatthe sample until the sample probe reaches thetarget temperature. If the probe is unplugged,heating power will be disabled until the probe isplugged into the rear connector.

To disable the heater plate and erase the plate orprobe target temperature, press the HEATEROFF key.

StirrerThe stirrer speed is set in a similar manner to thetarget temperature above except that theSTIRRER RPM key is pressed after the SET key.The target stirrer speed is rounded internally


Be sure the temperatureprobe is in the samplesolution and plugged intothe rear panel when heating.Failure to do so coulddamage your samplebecause the hot plate willdrive to maximum seeking atemperature it cannot find.

Caution

Enter

SET

9

HEATEROFF

2

PROBETEMP

Enter

SET

3

STIRRERRPM

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to a multiple of ten RPM. The stirrer may be setto any speed within the range 0 to 1500 RPM.However, the majority of the units are specified tooperate from 100 to 1200 RPM.

To turn off the stirrer, press the STIRRER OFFkey. This is the same as setting the stirrer speedto zero.

Timer

The timer counts in hours, minutes, and seconds.However, the user may only display or set thehours and minutes or the minutes and seconds ata given time. Setting the hours and minutes alsosets the seconds to zero. Setting the minutes andseconds sets the hours to zero.

The timer may be set to any count up to 99:99,however when the minutes or seconds roll overthey will be set to 59 as on a clock. For example,80 seconds may be set into the timer either as1:20 or as :80 minutes/ seconds. When the timerreaches zero it will alarm with three, unique,audible chirps.


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STIRREROFF

Note

Aluminum top, 10" x 10"Digital Hot Plate/Stirrersoperate from 100 to 800RPM.

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To set the timer in hours and minutes, press SETfollowed by TIMER HR:MIN. The seconds will beset to zero. Timing starts exactly when theENTER key is pressed.

To set the timer in minutes and seconds, pressSET followed by TIMER MIN:SEC key; enter thetime value in minutes and seconds and press theENTER key. The hours will be set to zero. Timingstarts exactly when the ENTER key is pressed.

Ramp

The ramp setting controls the rate at which thetemperature approaches the target temperature.The ramp values may be set within the range of 1to 555°C/HR or 1 to 999°F/HR. The unit canramp up or down depending on the targettemperature. A target temperature above thesample temperature will make the unit ramp up atthe specified rate. Likewise, a target temperaturebelow the sample temperature will make the unitramp down at the specified rate. The thermalcharacteristics of the sample and hot platedetermine the maximum rate at which thetemperature can ramp toward the target setting. Ifthe ramp setting is higher than this rate it can notbe attained.


Enter

SET

5

TIMERMIN: SEC

4

TIMERHR:MIN

Enter

SET

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To set the temperature ramp, press the SET keyfollowed by the RAMP

o/HR key; enter the ramp

value desired and press the ENTER key. To turnoff the ramping, set the ramp value to zero. Thiswill allow the heater to reach the targettemperature as rapidly as possible.

Entering Values

To set a value into the heater, stirrer, timer orramp, first the SET function is selected, anumerical value is entered, and then the ENTERkey is depressed.

As described previously, the SET function isselected by pressing the SET key followed by thekey of the function desired . When the SET key ispressed, the display shows all dashes withvertical doglegs (L L L L) . At this time only thesix settable function keys and the CLEAR keyare active. Pressing the CLEAR key will eraseSET and return the unit to the function that wasbeing displayed before SET was pressed.Pressing one of the function keys will cause thedisplay to show all zeros. At this point, the keysbecome numeric and the value may be entered.

Key in the value you wish to set, one digit at atime, up to four digits. The digits enter the displayfrom the right, calculator-style.

OPERATION

Enter

SET XXX

0 9–

6

RAMP0/HR

Enter

SET

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If you make a mistake, press the CLEAR keyand the display will return to all zeros. If you wishto exit from the SET function without actuallyentering a value, press the CLEAR key againwhile the display shows all zeros.

After keying in the desired value, press theENTER key. The new value will be entered atthis time and the function which was just set willbe displayed. If the value entered is out of range,however, it will not be accepted, and will be heldon the display until the CLEAR key is pressed.Once the value is accepted, the keys return totheir normal functions and no longer representnumeric data.

Auto-Off And Hold Functions

When the auto-off function is enabled, a time-outof the timer automatically turns off the heater andthe stirrer. This provides a convenient way topreset the length of time a sample is to beheated without the need for anyone to bepresent at the end of the period.

To enable the auto-off function, press theAUTO-OFF key and the lamp under the key willturn on. To disable auto-off, press the key againand the lamp will go out.


Enter

Set

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AUTOOFF

CLR

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Hold

When the HOLD function is enabled, the currentsettings of stirrer speed, target temperature andramp are placed into battery backed-up memory.When the 730 loses power or is turned off, thesesettings will be held in memory so that the unitwill return to them when power is restored. Thisfeature is very useful in case of a power failureduring unattended operation.

To enable the HOLD function, press the HOLDkey and the lamp under the key will turn on. Todisable HOLD, press the key again and the lampwill go off.

Other Modes of Operations

To use the DATAPLATE as a temperature meter,bring the sample to the unit and place thetemperature probe in the solution. Then touchPROBE TEMP and the temperature will bedisplayed.


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HOLD

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Timer

To use your 04644 Digital Hot Plate/Stirrer as alaboratory timer, simply touch SET, TIMERHR:MIN (or TIMER MIN:SEC), the time desired,then ENTER. As soon as the ENTER key istouched the unit will start to count down. It willbeep three times at zero.

Infrared Remote Control

The DATAPLATE 730 Series may be operatedremotely via an infrared signal originating fromthe Model 745 remote controller unit. The Model745 controller has the same functions as theModel 730 front panel. Infrared remote control isrecommended for situations in which the HotPlate/Stirrer unit is used under a closed fumehood or in a sealed chamber due to toxicconditions.

The 730 units may be operated at distances up to15 feet from the control unit. The infrared beamwill operate through glass windows. The intensityof the infrared signal decreases as the distancefrom the source increases. The strength of thesignal will also decrease as the viewing angle ofthe receiver varies from straight on. Thesefactors are important if one wishes to controlmore than one unit. It is recommended that theuser experiment with the placement of the


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controller module and the controlled units to findthe optimum configuration for controlling multipleunits.

Programs save you time on repetitive operations.They also free you to do other tasks while the HotPlate/Stirrer is performing your program. Once aprogram is written and corrected for mistakes, itmay be run time after time without error. The


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unit's program memory is backed by battery sothe program will be retained indefinitely evenduring intervals when power is off. You canexecute a program with just one keystroke. In thefollowing sections you will find instructions onhow to create and edit programs for unattendedoperation of the instruments in the 730 Series.

Editing A Program

During the creation of a program the display willshow the programmed steps as they are entered.When a program is being edited, each step may

Programmed Operation

Note

The figure shown above issimilar to that in Section VIexcept the key labels shownare those which refer toprogrammed operation only.The other labels have beenexcluded for the sake ofclarity.

Front Panel

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be displayed and edited as the program is viewedin forward or reverse sequence. The modifiedprogram may then be displayed prior toexecution.

Press this key to enter or edit a program. Whenthe EDIT key is pressed, the display will showtwo zeros to the left of a period. The zeros signifythat you are at the beginning of a series ofprogrammed steps. At this point you may createa program or edit one which already exists. Whenediting operation has been completed, press thiskey to exit the EDIT mode and return to normaloperation.

Press this key to view a program in forwardsequence. Each time the STEP UP key ispressed the display will show the next step in theprogrammed sequence. When you have reachedthe last step in the program, pressing the key willhave no effect.

Press this key to view a program in reversesequence. Each time the STEP DOWN key ispressed the display will go from a higher step to alower step in the programmed sequence.Pressing this key will have no effect when youhave reached step 00.

The OMIT key has a dual function which dependson the mode in which the unit is operating. In theedit or programming mode, the OMIT function isoperative. When this key is pressed, the

PROGRAMMED OPERATION

6

EDIT

8

STEPUP

7

STEPDOWN

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programmed step currently in the display will beerased. If step 00 is in the display, pressing thiskey will erase the entire program.

Placing a set of programmed steps into thememory of any of the models in the 730 Series ofHot Plate/Stirrer units is a simple task once theuser is familiar with the functioning of the variousprogramming keys.

There are four types of program steps. They are:

1. DISPLAYPress a display key (PLATE TEMP, PROBETEMP, STIRRER RPM, TIMER HR:MIN, orTIMER MIN:SEC) to enter a display step. Whenthe program executes, this step will cause thedisplay to indicate as instructed.

2. SETEnter a target value as done normally.(EXAMPLE: SET, PROBE TEMP, 1, 0, 0,ENTER). When the program is run, the targetvalue will be set.

3. HEATER OFF/STIRRER OFFPress either of these keys to enter a step whichwill turn off the heater or stirrer when it executes.

4. WAIT UNTIL


Note

There are a maximum of 75program steps allowable.

CLR

OMIT

33

A WAIT UNTIL step is similar to a SET step.When executed, it sets the target value just likethe SET step, but the execution of the followingprogram step is delayed until the target value isreached. WAIT UNTIL may only be used with atarget temperature or a timer setting. It will notwork with stirrer speed or ramp value. Theoperation of the WAIT UNTIL feature is describedbelow.

In programmed operation this key will togglebetween the SET and WAIT UNTIL functions.When the key is pressed once, it will be in theSET mode. When it is pressed a second time, itwill be in the WAIT UNTIL mode.

If the WAIT UNTIL step sets the timer, then it willalso introduce a time delay into the program. Ifthe WAIT UNTIL step sets a target temperature,then the execution of the remainder of theprogram will be delayed until the targettemperature has been attained.


ENT

WAITUNTIL

SET

34

To set a time delay into the program, firstpress the WAIT UNTIL key twice. The firsttime it is pressed a series of dog-leggeddashes will fill the display. The second time itis pressed a series of U's will fill the display.The U's will be shown whenever the key is inthe WAIT UNTIL mode. Next, press eitherthe TIMER/HR:MIN or the TIMER/MIN:SECkey and set the time as described previously.Last, press the ENT key to indicate that thestep is complete.

To cause the program to delay until a targettemperature is reached, repeat the processabove but press either the PLATE TEMP orPROBE TEMP key and then set the targettemperature.

Running A Program

Once a program has been entered into theunit, it may be run at any time.

Pressing this key when the unit is not in theedit mode will initiate the program which iscurrently in program memory. While theprogram is running, the lamp under this keywill light. Pressing this key while the programis running will cancel any remaining steps inthe program and turn off the RUN lamp.


CLR

RUN

35

It is important to remember that all programsteps take only an instant to execute with theexception of "WAIT UNTIL" steps. Compare thefollowing program steps:


STEP ACTION

SET PROBE 100° Set target temperature.Executes next step while unit

OR begins to go toward target.

WAIT UNTIL PROBE 100°C Sets target temperature as above.Next program step does not executeuntil probe temperature reaches 100°.

SET TIMER MIN:SEC 00:05 Puts 5 seconds on the timer thenexecutes next step as timer begins tocount.

OR

WAIT UNTIL TIMER MIN:SEC 00:05 Waits 5 seconds before continuing program.

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During the time that a program is running, youmay press any key to change the display or to setnew values of temperature, stir speed or time.You may not, however, edit a program while it isrunning. Pressing the EDIT key while a programis running has no effect.

If the power fails during the running of a program,the program is aborted. It must be run again fromthe beginning when power is restored. All of thestored program steps will be retained during thepower failure.

EXAMPLE PROGRAM

Now that all of the key functions have beendefined, it is time to place a program in memoryand run it. We will begin with a very simpleprogram. We wish to place the temperature probein a liquid which will be heated to 105°C, held atthat temperature for 30 minutes and then cooledback to room temperature. We will heat slowly ata predetermined rate and use the stirrer to spreadthe heat uniformly throughout the liquid. Here isthe sequence of keystrokes along with the relateddisplay. (To enter the edit mode, remember topress the EDIT key).


STEP NUMBER KEYSTROKE SEQUENCE EXPLANATION

01. Set stirrer to 100 RPM13

STIRRERRPM

SET 1 1 Enter

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02. Display stirrer RPM

03. Wait 15 seconds

04. Set ramp valueto 50°/HR

05. Display the probe temp

06. Wait until probe temp= 105°C

07. Set 30 minute time delay

08. Turn heater off

3

STIRRERRPM

1 5 Enter

WAITUNTIL

WAITUNTIL

5

TIMERMIN:SEC

5 0 Enter

SET

2

PROBETEMP

0 5 Enter

WAITUNTIL

WAITUNTIL

2

PROBETEMP

1

8

RAMP°/HR

9

HEATEROFF

3 0 Enter

WAITUNTIL

WAITUNTIL

4

TIMERHR:MIN

38

The program is now complete. Whenever theRUN key is pressed, the Hot Plate/Stirrer willexecute the program steps in the order in whichthey were entered. It is now possible to leave theunit while it performs the task unattended.

Steps 2 and 5 were inserted as a check onprogram operation. The first will display stirrerRPM while the second displays the probetemperature throughout the remainder of theprogram operation. A 15 second delay wasinserted after the "display stirrer RPM" commandto allow time for the stir bar motor to reach targetspeed while the stirrer RPM is being displayed.



09. Wait another hour

10. Turn stirrer off

0 0 Enter

WAITUNTIL

WAITUNTIL

4

TIMERHR:MIN

1

0

STIRREROFF

39

Before leaving the unit in unattended operationwith a program which has not been previouslyrun, it is a good idea to do a test run while inattendance. After the RUN key is pressed, thedisplay will show stirrer RPM for 15 seconds.Make sure that the value is the same as that setinto the program to within ±20 RPM. For theabove example, this will be 100 RPM.

After the stirrer speed, the probe temperature willbe displayed. Check to see that it ramps up at theprogrammed rate and then stops at the targettemperature (1-5°C). If there have been no errorsin entering the program, the temperature willremain at 105°C for 30 minutes before coolingdown to room temperature. One hour after thecool down begins, the stirrer should ceaserotating.

If the initial checkout does not yield all of theresults described above, then the program has anerror or omission in one or more steps. Correctingor modifying an existing program will bedescribed in the next section.


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Modifying A Program

The user can change any of the values oftemperature, time, stirrer speed or ramp rate inthe editing process. For example, assume thatwe wish to change the target probe temperaturein the above example from 105° to 100°C. Usethe STEP UP key to proceed to step 6 in theprogram. The display shows: 06.U2. Press theOMIT key to erase the step. The display will nowread 06.U4 as step #7 has now become step #6.Next press the STEP DOWN key to display setup#5. Then press the SET and the PROBE TEMPkeys followed by the digits 1, 0, 0. Finally pressthe ENTER key. The target temperature will nowbe 100°C for all subsequent runs of this program.

There are two rules to remember whendeleting or inserting steps.1. When a step is deleted, all of the steps whichwere entered after it move up one position in theprogram.2. When a step is inserted, it is inserted after thestep in the display. All subsequent steps aremoved up one position. The preceding steps arenot affected. For example, if you wish to insert astep between steps 8 and 9, step through theprogram until step 8 is in the display, then insertthe key stroke sequence. When adding a step atthe end of a program, step through the programuntil the last step is in the display, then add thestep.


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Temperature Calibration

The temperature readouts for both the platesurface and the probe may be calibrated by theuser. Two rear panel adjustments are providedfor each temperature channel.

PROBE READOUT CALIBRATION

Probe calibration is performed using anaccessory calibration kit which preciselysimulates fixed temperature points. The kit (part# 710-5001) has a high temperature "dummy"probe which when plugged into the probeconnector presents the same value of resistanceto the internal temperature analyzing circuitry asthe RTD probe at the temperature which iswritten on the calibrator case. There is also a lowtemperature plug-in which simulates theresponse at the temperature called out on thecalibrator case.

To calibrate the probe readout, first insert thehigh temperature "dummy" probe into thetemperature probe DIN connector located on therear panel. Then adjust the calibration pot

Maintenance

42

marked PROBE HI until the front panel readoutagrees with the temperature stamped on the"dummy" probe. When the high temperature hasbeen adjusted, repeat the procedure with the lowtemperature probe module by adjusting thepotentiometer marked PROBE LO to agree withthe temperature marked on the "dummy" probe.The probe readout calibration is now complete.The calibration must be carried out in the orderspecified above (Hi temp; Low temp).

PROBE CHECK

The optional probe supplied by Barnstead|Thermolyne comes with the followingspecifications:

PROBE TYPE - DIN 43760 "CLASS B"

PROBE ACCURACYTEMPERATURE (°C) TOLERANCE

0 ±0.3°100 ±0.8°300 ±1.8°

If it is desired to adjust the unit to compensate foran error at a particular temperature, this may bedone using the LO TEMP pot. Place the probe inthe liquid which is at the temperature of interestand adjust the LO TEMP pot until the readout iscorrect. This procedure will introduce error into

MAINTENANCE

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the system at other temperatures so rememberto readjust the probe readout when using a newprobe or when you wish to have readoutaccuracy over a broad range of temperatures.

The probe may not be used at temperaturesbelow 0°C since the readout will not respond inthat region.

Helpful Hints

A. Use on a level surface when stirring,especially when stirring violently. If the unit is notlevel, the sample container will "walk", and couldwalk right off the plate.

B. Stirring thicker solutions may require using alarger stir bar. Generally, the more viscous asolution, the larger the stir bar needed. For bestoperation overall, it is recommended that the stirbar match the magnet poles in the stirrer. Theseare 2 inches apart.

Caution

Always disconnect the powercord before removing thebottom plate.

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C. Temperature targets may overshoot, especiallywith small liquid samples and when targettemperature is close to ambient. If it is importantnot to overshoot, try ramping up to the target.Alternatively, target your temperature 5°C to 10°Cbelow the desired temperature. When thetemperature is reached, slowly ramp the unit tothe final temperature.Temperature overshoot is generally less than5°C. Large samples and target temperatures over100°C very seldom overshoot.

D. When entering a new program into memory,always clear the previous program. This is doneby pressing the OMIT key when the display isshowing step 00.

E. On multistirrer units, place the probe in one ofthe vessels on the corner of the unit. This willensure the most uniform sample temperaturesdue to the symmetry of the arrangement.

BATTERY REPLACEMENT

The battery used in all 730 Series instruments isa 3 volt Lithium battery which should have auseful lifetime of at least 5 years. Thereplacement battery is available fromBarnstead|Thermolyne. Instructions for replacingthe battery are given below.

MAINTENANCE

Battery Replacement

45

Turn the unit over so that it rests on the hot plate.Use a soft cloth or paper towel between the platesurface and the workbench to ensure that theplate is not marred or scratched in the operation.Use a phillips screwdriver to remove the fourscrews which hold the bottom in place.

With the unit arranged so that the keyboard facesforward, the battery PC board is directly behindthe front panel display on the far right. Thepicture below shows the approximate location ofthe battery on the board.

The battery is held in place with a metal clip in aplastic case. To remove the old battery, place asmall flat metal blade into the forward section ofthe case (as shown in the figure on page 44) andpry upward until the sides of the battery areexposed sufficiently to force the battery out witha finger placed on either side. A small, flat-bladescrewdriver, pocket knife blade, metal nail file orsimilar object may be used for this operation.

To insert the new battery, hold the clip up andslide the battery into the case until it rests in a flatposition. Make certain that the positive side ofthe battery faces up. The battery will not fall intoplace properly if it is not positioned correctly.

Now replace the bottom plate and the power cordand the unit is ready to operate.

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PROBLEM WHAT TO DO/EXPLANATION

1. The sample temperature does notrise as rapidly as the programmedramp value.

2. The probe temperature does notdisplay 100°C or 212°C whenimmersed in boiling water.

3. The probe temperature readoutdoes not display 0°C or 32°F whenimmersed in an ice bath.

4. The sample temperature readingremains higher than the targettemperature.

5. The probe temperature reads alldashes.

6. The stir bars are revolvingerractically.

Try heating a smaller sample. The heatingcapacity of the DATAPLATE Heater/Stirrer isprobably not adequate to raise the sampletemperature at the programmed rate.

If you are in a location which is 1000 ft.or more above sea level your boiling point willdecrease.

OR

perform the probe calibration procedure givenon p.27.

Check the purity of the water. Dissolvedsubstances will usually lower the freezing pointof water.

OR

Perform the probe calibration procedure givenon p. 27.

Check the ambient temperature. The targettemperature may be below room temperature.

Check to see that the probe plug is seatedtightly and making contact. If it is not makingcontact the readout will default to dashes (- - - -).

Check to see that the sample containers arecentered over the stir bar motors.

OR

The stir bars may not be able to maintain propercoupling to the motor magnets due to theviscosity of the sample.

Troubleshooting

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PROBLEM WHAT TO DO/EXPLANATION

7. The unit or units do not respond toinfrared remote control

8. In programmed operation, the unitcontinues to execute commands aftercompleting the program which hasbeen entered.

9. The unit does not hold the programin memory with the power off.

Move the 745 controller closer.

OR

Check the angle between the controller andunits.

OR

Clean the infrared windows on all units.

Be sure that you have cleared the memorybefore entering the new program. If you havenot, the extra steps may be erased with the unitin the EDIT mode.

The battery needs to be replaced.

TROUBLESHOOTING

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2555 Kerper BlvdP.O. Box 797Dubuque, IA 52004-0797 USAPHONE: 319-556-2241FAX: 319-556-0695 • 319-589-0530E-Mail Address: [email protected]

Documents

DATAPLATE Digital Hot Plate/Stirrer · The DATAPLATE Hot Plate/Stirrer Series 730 is a programmable, general purpose, digital laboratory hot plate with stirrer. The series includes