Manual for the

Digital Salt-in-Crude Analyzer Model SC-960

Walter Herzog GmbH Badstrasse 3-5, PO box 1241

97922 Lauda-Konigshofen, Germany Tel (49) 9343 640 0 Fax (49) 9343 640 101

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SC-960 Digital Salt-in-Crude Analyzer

Introduction

The Model SC-960 Digital Salt-in-Crude Analyzer is a simple-to-operate laboratory analyzer that automatically measures the salt content of crude oil on the ASTM (D 3230) and other conductivity scales. It features a non-volatile memory which stores up to three different calibration curves.

In addition, the optional VI-CAL Calibration Program allows you to generate and store any number of calibration curves on a non-dedicated IBM compatible PC. These curves may be downloaded as required to the SC-960. See the separate VI-CAL software manual for more information.

Principle of Operation

The SC-960 determines salt content by measuring its conductivity and comparing that value to a calibration curve. To perform a measurement, a sample solution is prepared per ASTM standards and placed in a measurement beaker. A stainless steel electrode assembly is then lowered into the solution and a low level (millivolt) excitation voltage applied.

The SC-960s solid state circuitry automatically measures the conductivity; a microprocessor compares the value to the programmed calibration curve and digitally displays the salt content in the users selected units. Corresponding analog and serial output signals are also generated.

The SC-960 also incorporates user-settable dual-level alarms. These visual indicators permit quick go/no go checks of multiple samples.

Safety Guidelines

Your safety is of utmost concern when operating this instrument. Operation outside the parameters listed in the specifications could possibly result in personal injury and/or serious damage to the instrument or its critical parts. Repairs, alterations, and/or modifications by anyone other than a factory authorized service representative will void the Warranty.

All personnel should carefully adhere to the following general safety procedures as well as other prevailing safety regulations for the area where the instrument is used.

Always wear safety glasses when working with or around the equipment. If flammable or other hazardous materials are involved in the measurement, locate the Beaker Holder

inside a properly adjusted fume hood.

When the necessity for cleaning arises, exercise care in the selection of a cleaning solvent. The solvent selected should not attack the painted, plastic, or other instrument components. Avoid inhalation of fumes and prolonged contact with skin. Follow the manufacturers recommendations for safe handling and use.

This instrument is a laboratory instrument and is not designed or to be used as a portable instrument.

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Specifications

Performance Specifications

Calibration: Accepts multiple calibrations, including ASTM D 3230 and other conductivity-based salt content standards.

Ranging: Automatic ranging.

Repeatability: 2% or better.

Operating Temperature Range: 0 to 40C (32 to 104F).

Electrical Specifications

Power: 100 to 240 VAC, 50/60 Hz., 15 watts, 1 phase.

Signal Outputs

Digital Display: 3-1/2 digit LED.

Analog Output: 0 to 2.5 VDC analog.

Serial Output: RS-232.

Alarms: User-settable dual-level with visual alarm indicators.

Physical Dimensions

Electronics Module: 185 (W) x 64 (H) x 250 (L) mm (7.29 x 2.52 x 9.84 inches).

Beaker Holder: 108 (W) x 51 (H) x 108 (L) mm (4.25 x 2.00 x 4.25 inches).

Due to our commitment to continual product improvement, specifications subject to change without notice.

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Component Identification

Electronics Module, Front Panel (Figure 1)

Digital Display A 3-1/2 digit LED which displays the measured value and other information.

L (Low) Alarm LED A yellow LED which lights whenever the salt concentration drops below the Low alarm setpoint.

H (High) Alarm LED A red LED which lights whenever the salt content exceeds the High alarm setpoint.

SET Button Used to scroll through the analog output and alarm value setup procedures. May also be pressed during normal operation to determine or change the active calibration table.

AUTO ZERO Used to adjust the baseline value prior to making measurements. May also be used in conjunction with the SET button to change the active calibration table.

TEMP ADJ (Temperature Adjustment) A potentiometer which permits the user to adjust the current temperature value when acquiring data.

Input Ports Two jacks used for connecting the Cable Set from the Beaker Holder.

ALARM

L HAUTOZERO

SET

TEMPADJ

Figure 1

ALARM LEDs SIGNAL INPUT PORTS

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Electronics Module, Back Panel (Figure 2)

Line Cord Connection An IEC connection for the power cord (supplied).

Power Cord A three-conductor cord that connects the IEC connection on the back panel to the line voltage receptacle.

WARNING: Do not, under any circumstances, alter the power cord or revise the grounding. CAUTION: Be sure the power supply for your instrument is of the same voltage as that specified for

the instrument.

Power Switch A rocker switch that controls electrical power to the Analyzer.

Fuses 100 to 120 VAC (1 amp 250V IEC 127-2) or 220 to 240VAC (0.5 amp 250V IEC 127-2) fuses which cut electrical power to the instrument in the event of an unacceptable spike in incoming voltage or other electrical malfunction.

SERIAL (RS-232 Serial Port) A 9-pin serial D connector for attaching the Analyzer to an HP Palm Top or compatible computer. This connection permits both the generation and downloading of calibration curves when used with VI-CAL.

NOTE: An inverting null modem (not supplied) must be used to connect to an IBM PC or compatible. ANALOG OUT (Analog Output Ports) Two terminals for connection to a strip chart recorder. The Analyzer produces a linear analog output signal whenever conductivity measurements are being made. The analog output signal is normally 0 to 2.5 VDC. The measurement values that correspond to the lowest and highest analog signals are programmed during calibration table generation. Refer to the separate VI-CAL instruction manual for additional information.

IMPORTANT: Cables/leads from the SC-960s serial and analog outputs to external devices must not exceed one meter (36 inches) in length

Figure 2

.

FUSE REPLACEMENT USESAME TYPE/RATING

100~240 VAC 50/60 Hz 1 PH.

SERIAL

ANALOG OUT

WARNING

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Beaker Holder (Figure 3)

Beaker Holder A specially designed block that supports the Cable Set, Electrode Set, and two 100 mL tall form beakers.

Cable Set and Post The cable is secured by a spiral binding to a supporting rod with a threaded end. The cable connects the Electrode Set to the front panel.

Electrode Set A stainless steel assembly which applies a millivolt signal to the sample solution.

NOTE: The standard electrode set meets ASTM D 3230 specifications. Do not alter cable set in any way.

Figure 3

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Instrument Setup

Location

To obtain the most uniform results from the Analyzer, choose a location remote from drafts, ventilating outlets, radiators, and other sources of rapidly changing conditions. The cooling fan draws air through the bottom of the Electronics Module, so place the module on a flat surface and do not permit anything to obstruct air flow beneath the module. To assure proper ventilation, allow a minimum of 310 mm (12 inches) clearance at the rear, top, sides, and front of the module.

WARNING: If flammable or other hazardous materials are involved in the measurement, the Beaker Holder should be located in a properly operating fume hood.

Electrical Connections

NOTE: For optimum operating accuracy, a steady, noise-free line voltage source is recommended for this instrument.

CAUTION: Be sure the power source used for the instrument is of the same voltage as that specified for the instrument.

WARNING: For personal safety, this instrument must be properly grounded. WARNING: Do not, under any circumstances, alter the power cord or revise the grounding. The instrument incorporates an IEC connection for use with its companion power cord. Plug the IEC connector on the power cord into the connection on the instrument; plug the power cord into the appropriate electrical outlet.

The power cord of this instrument is equipped with a three-prong (grounding) plug which mates with a standard three-prong (grounding) receptacle to minimize the possibility of electrical hazard. The user should have the wall receptacle and circuit checked by a qualified electrician to make sure the receptacle is properly grounded. Where a two-prong receptacle is encountered, it is the personal responsibility and obligation of the user to have it replaced with a properly grounded three-prong receptacle.

NOTE: A two-prong power cord may be shipped with the instrument in some instances; see instructions accompanying cord for proper installation.

Beaker Holder Connections

Install the post in the beaker holder.

At the end of Cable Set farthest from the post, insert the plugs into the Input Ports on the front panel of the Electronics Module.

At the opposite end of the Cable Set, insert the plugs in the jacks on the Electrode Set.

Power On

Place the rocker switch on the back panel of the Electronics Module in the on position.

Analog Connections

If the analog output signal will be sent to a recorder or other external device, make the connections at the Analog Output ports on the back panel of the Electronics Module. Connect the + lead to the red terminal and the - lead to the black terminal.

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High Analog Output (Span) Adjustment

Press and hold the SET button on the front panel of the Electronics Module until H appears on the digital display. The instrument will output a 2.5 VDC analog signal so external devices can be adjusted.

Low Analog Output (Zero) Adjustment

Press and hold the SET button a second time; L will appear on the digital display. The instrument will output a 0 VDC analog signal so that external devices can be adjusted.

RS232 Serial Connection

This connection is used to link the Analyzer to an HP Palm Top or similar computer and permits the generation and loading of calibration curves as well as the setting of salt concentration alarm values when used with the optional VI-CAL calibration software (see separate manual).

Plug the female connector of the serial cable into the D connector on the back panel of the Electronics Module; plug the male connector into the serial port of the PC.

NOTE: Port pins are wired to be compatible with an HP Palm Top computer. Use of other PC computers may require a cross-over null modem (contact factory for information).

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Normal Operation

Power On

Place the rocker switch on the back panel of the Electronics Module in the on position. Upon power up, the following information will appear in sequence on the Analyzers digital display:

Active table ID# or dEF (default) H (high analog output) L (low analog output) High alarm value Low alarm value Temperature

NOTE: There are no alarm values in the default (dEF) table. After the Temperature appears, the Analyzer will automatically enter the measurement mode, displaying the current measured value.

Calibration Selection

NOTE: To determine the Analyzers active calibration table, briefly press the SET button on the front panel of the Electronics Module. The table ID# or dEF (default) will appear briefly on the Analyzers digital display: e.g. factory calibration #301, 0-100 PTB; factory calibration #100, 0-450 mg/L.

The active calibration table may be changed from either the front panel of the Analyzer or through the optional VI-CAL Calibration Program.

Analyzer Press and hold the SET button to display the active calibration table ID#. When the ID# appears on the digital display, press the AUTO ZERO button to scroll through the tables which are currently resident in the instrument.

When the ID# for the desired table is displayed, release the AUTO ZERO button and the SET button; the unit will automatically return to normal operation.

VI-CAL Refer to separate VI-CAL instruction manual.

Automatic Zero

The baseline measurement of the Analyzer may be adjusted by loading a sample equal to a calibrations lowest display value in the Beaker Holder and pressing the AUTO ZERO button. The unit will automatically readjust its readings (zero offset) to reflect the new baseline.

EXAMPLE: The display range for a calibration is 0 to 100. A blank (or 0 sample) gives a 2 reading. Pressing the AUTO ZERO button will readjust the measurement baseline to read the blank as 0; all other measurement values will also be readjusted accordingly.

NOTE: The automatic zero function may be used when making measurements using the default calibration table; however, caution is advised. If AUTO ZERO is inadvertently used with the default table, or you wish to remove a previously selected zero offset, you can return to the programmed default baseline by turning the power off and then back on. Turning the power off will not affect the automatic zero value when using any other calibration table.

Sample Preparation

The following equipment and reagents are required to properly prepare samples and calibration standards:

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Graduated cylinders (100 and 1000 mL) Graduated pipettes to contain 1, 5, 10, and 25 mL Balance Volumetric flasks (100 mL) Graduated, glass-stoppered mixing cylinders (100 mL) Mixed Alcohol Solvent (630 mL of 1-butanol mixed with 370 mL of absolute methanol; mix this

solution with 3 mL of distilled water). Xylene that meets the requirements of ASTM D 843. Neutral oil, salt-free, free of additives, with a viscosity of approximately 100 SSU at 37.8C (100F);

for blank preparation (see Appendix). Naphtha that meets the requirements of ASTM D 91 (for cleaning). WARNING: The alcohol solvent, xylene, and naphtha are flammable and harmful if inhaled. Use

them only in a properly operating fume hood.

To prepare a sample of crude oil for determination of salt content, use the following procedure:

1. Add 15 mL of xylene to a dry, glass-stoppered 100 mL graduated cylinder.

2. Using a to contain transfer pipette, add 10 mL of the crude oil to the graduated cylinder.

3. Rinse the oil from the pipette with xylene and pour the mixture into the graduated cylinder.

4. Add xylene to the cylinder until the total volume in the cylinder equals 50 mL.

5. Place the stopper in the cylinder and shake vigorously for at least 60 seconds.

6. Add mixed alcohol solvent to the sample in the graduated cylinder until the total volume equals 100 mL. Stopper and shake vigorously for 30 seconds.

7. Allow the mixture to stand for five minutes, then measure the salt concentration as outlined below.

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Making Salt Content Measurements

Place the entire 100 mL sample in a beaker in the Beaker Holder. This ensures that the electrodes will be completely covered.

Insert the electrodes into the sample so that the plastic cap of the Electrode Set rests firmly on the edge of the beaker. The measurement value will appear on the Analyzers digital display. A corresponding analog signal will also be generated.

For maximum repeatability, measure the conductivity as soon as possible after the 5 minute standing time.For maximum accuracy, allow the reading to stabilize before removing the sample for a subsequent measurement.

IMPORTANT: If the measured value is outside the range of the instrument (too high or too low), all decimal points on the display will light and the display will go to either its highest (high reading) or lowest (low reading) programmed limit.

Temperature Compensation

Each calibration table selected contains a calibration temperature and programmed temperature coefficient. The SC-960 will automatically correct the conductivity measurement per the programmed coefficient. Factory calibration tables supplied with the unit have a temperature coefficient set to 0 (zero).

To adjust the instrument, first display the current temperature setting (see Checking Programmed Values, below) and then use a small, straight-blade screwdriver to turn the TEMP ADJ potentiometer until the displayed value matches the actual sample temperature.

Salt Content Alarms

If the Analyzers High and/or Low alarms have been set using VI-CAL, any measurement outside the established parameters will activate the appropriate alarm LED.

NOTE: There are no alarm values in the default table or factory supplied calibrations ID #100 and #301.

Checking Programmed Values

To check programmed values and/or adjust external recording devices for a loaded calibration, press and hold the SET button. H will appear on the digital display and the unit will output the high analog signal to permit the adjustment of external devices.

Press the SET button a second time; L will appear on the display and the low analog signal will be generated.

Press the SET button again. The high alarm value will appear on the display and the red LED will light.

Press the SET button a fourth time. The low alarm value will be displayed and the yellow LED will light.

Press the SET button again. Two dashes will appear followed by the temperature display. The displayed temperature can be adjusted to match measurement temperature at this point. See Temperature Compensation above.

Press the SET button once more to return to the measurement mode.

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Appendix

Preparing Calibration Standards

The SC-960 Digital Salt-in-Crude Analyzer is factory calibrated with solutions of known salt concentration. This section details the preparation of the standard solutions. Procedures for generating a calibration table are described in the separate VI-CAL Instruction Manual.

Required Equipment Graduated cylinders (100 and 1000 mL) Graduated pipettes to contain 1, 5, 10, and 25 mL Balance Volumetric flasks (100 mL) Graduated, glass-stoppered mixing cylinders (100 mL) Required Reagents

WARNING: The alcohol solvent, xylene, and naphtha are flammable and harmful if inhaled. Use them only in a properly operating fume hood.

Mixed Alcohol Solvent (630 mL of 1-butanol mixed with 370 mL of absolute methanol; mix this solution with 3 mL of distilled water)

Xylene that meets the requirements of ASTM D 843.

Neutral oil, salt-free, free of additives, with a viscosity of approximately 100 SSU at 37.8C (100F).

Naphtha that meets the requirements of ASTM D 91 (for cleaning).

Standard Salt Solution

A standard salt solution is prepared as follows:

1. Prepare solutions (10.0 g/L) of calcium chloride, magnesium chloride, and sodium chloride by dissolving 1.0 g of each salt in 25 mL of distilled water and then diluting to 100 mL with alcohol solvent in volumetric flasks.

2. Prepare a mixed salt solution by pipetting 10 mL of the calcium chloride solution and 20 mL of the magnesium chloride solution into a 100 mL volumetric flask. Add 70 mL of the sodium chloride solution to this mixture (for a total volume of 100 mL).

3. Pipette 1.0 mL of the mixed salt solution into a 100 mL volumetric flask. Add 99 mL of alcohol solvent to obtain a standard salt solution with a concentration of 0.1 g/L.

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Standard Preparation

To prepare each standard, take the following steps:

1. Add 15 mL of xylene to a clean, dry, 100 mL mixing cylinder.

2. Add 10 mL of neutral oil from a to contain pipette.

3. Rinse the oil from the pipette with xylene and pour into the mixing cylinder. Add xylene until the total volume in the cylinder equals 50 mL.

4. Insert the stopper in the cylinder and shake vigorously for at least 60 seconds.

5. Pipette in the volume of standard salt solution shown in the table below.

6. Rinse the pipette with alcohol solvent and pour into the mixing cylinder. Add alcohol solvent until the total volume in the cylinder equals 100 mL.

7. Insert the stopper and shake for at least 30 seconds.

8. Let the mixture stand for 5 minutes before you use it in the generation of a calibration table.

NOTE: Salt solutions have limited shelf life and must be prepared fresh for each calibration. Composition of Standards Volume, mL

Standard, PTB*

Xylene Neutral Oil Xylene Salt Solution

Alcohol Solvent

Blank 15 10 25 0.0 50.0

3.0 15 10 25 0.9 49.1

10.0 15 10 25 3.0 47.0

20.0 15 10 25 6.0 44.0

30.0 15 10 25 9.0 41.0

50.0 15 10 25 15.0 35.0

75.0 15 10 25 22.5 27.5

*Salt as sodium chloride, pounds per 1000 barrels of crude oil.

Fuse Replacement

WARNING: Be sure to remove all power to the instrument before replacing the fuse. The mains fuses are located on the back panel of the Electronics Module. To replace, open the fuse drawer and remove the blown fuse. Replace with new fuses of the proper type. Close fuse drawer and restore power to the instrument.

WARNING: Internal fuses (power supply and analog output) must be serviced only by qualified factory representatives.

ManualSC-960Digital Salt-in-Crude AnalyzerIntroductionPrinciple of OperationSafety GuidelinesSpecificationsPerformance SpecificationsElectrical SpecificationsSignal OutputsPhysical Dimensions

Component IdentificationElectronics Module, Front Panel (Figure 1)Electronics Module, Back Panel (Figure 2)Beaker Holder (Figure 3)

Instrument SetupLocationElectrical ConnectionsBeaker Holder ConnectionsPower OnAnalog ConnectionsHigh Analog Output (Span) AdjustmentLow Analog Output (Zero) AdjustmentRS232 Serial Connection

Normal OperationPower OnCalibration SelectionAutomatic ZeroSample PreparationMaking Salt Content MeasurementsTemperature CompensationSalt Content AlarmsChecking Programmed Values

AppendixPreparing Calibration StandardsComposition of StandardsFuse Replacement