Instruction Model SC200 Manual 2-wire Conductivity...The EXA SC200 transmitter is a 2-wire...

InstructionManual

Model SC2002-wire Conductivityor Resistivity transmitter

IM 12D7B2-E-H4th edition

IM 12D7B2-E-H

FAILHOLD

MEASURECALDISPLAYHOLD

YES NO

ENT

OUTPUTSET HOLDT E M P.SERVICE

*NO MODEYES

> ENT>

MODE

m S / c mM Ω / c m

k Ω / c mµ S / c m

.

ADJUSTMENT KEYS

: Choose digitfor adjustment

: Adjust digit (to decrease pass through zero)

ENT: Enter new value

MEASURE VALUEDISPLAY

MESSAGEDISPLAY

KEY PROMPTFLAGS

SELECTION KEYSYES: Accept

settingNO: change to

new setting L

L

SELECT MODEMEASURE/MAINTENANCE

Can be usedto escapeprogram at any time

SELECT MODEMEASURE/COMMISSIONING

OUTPUTHOLD FLAG

MANUALLY SETTEMPERATURECOMPENSATIONFLAG

FAILFLAG

MENU POINTERFLAGS

MENU FORMAINTENANCEFUNCTIONSsee chapter 5

MENU FOR COMMISSIONINGFUNCTIONSsee chapter 4

Note: First digit changes from 1,-1,- to blank.

TEMP.MAN

IM 12D7B2-E-H

1. INTRODUCTION1-1. Application.................................................................11-2. Required components for

conductivity measurement .........................................11-3. Identification...............................................................2

2. TECHNICAL SPECIFICATIONS .........................................22-1. General technical specification ...................................22-2. Functional description ................................................3

3. INSTALLATION AND WIRING ............................................43-1. Installation and dimensions ........................................4

3-1-1. Installation site.................................................43-1-2. Mounting methods ..........................................4

3-2. Wiring of sensors .......................................................63-2-1. General precautions ........................................63-2-2. Additional precautions for installations in

hazardous areas..............................................63-2-3. Grounding the liquid ........................................63-2-4. Access to terminal and cable entry..................63-2-5. Connecting diagram for sensors......................7

3-3. Wiring of power supply...............................................83-3-1. General precautions ........................................83-3-2. Additional precautions for installation

in hazardous areas ..........................................83-3-3. Access to terminal and cable entry..................83-3-4. Power on ........................................................8

4. COMMISSIONING.............................................................114-1. Operations overview ................................................114-2. Output range adjustment ............OUTPUT ..............124-3. Set up Hold function ...................SET HOLD ...........144-4. Temperature compensation ........TEMPERATURE ...164-5. Sensor selection and diagnostics` ............................18

5. MAINTENANCE.................................................................205-1. Calibration...................................CAL......................205-2. Selecting a value to display .........DISPLAY ..............225-3. Use of the hold function ..............HOLD...................24

6. TROUBLE SHOOTING ......................................................266-1. Introduction .............................................................266-6. Error messages and explanation ..............................27

7. SERVICE (Mode) ...............................................................287-1. Introduction .............................................................287-2. Access to service settings........................................297-3. Temperature sensors and units................................307-4. Reference temperature ............................................307-5. Output code selection..............................................307-6. Output table for non-linear range .............................317-7. Cell constant adjustment..........................................317-8. Auto return function .................................................317-9. Measuring principle..................................................327-10. Temperature sensor adjustment...............................327-11. Signalling of fail condition .........................................327-12. Temperature compensation coefficient adjustment ..337-13. Percent by weight indication on second

display line ...............................................................347-14. Polarisation check....................................................347-15. Passcode protection by three digit code ..................357-16. Restore default setting .............................................357-17. Non linear ranges.....................................................36

CONTENTS

IM 12D7B2-E-H

8. CLASSIFICATION .............................................................368-1. Cenelec ...................................................................368-2. FM...........................................................................37

9. CHANGE FROM CONDUCTIVITY TORESISTIVITY MEASUREMENT ............. ............................389-1. How to change from conductivity to resistivity

measurement...........................................................389-2. Resistivity measurement ..........................................389-3. Maintenance of the transmitter.................................38

10. SOFTWARE VERSION 3.0 COMPARED TO VERSIONS 1 AND 2 ............................3910-1. Cell constant............................................................3910-2. Matrix compensation ...............................................3910-3. Matrix temperature-compensation range .................4010-4. Matrix data...............................................................4010-5. Selection between “soft” or “hard” Fail situations .....4110-6. Selection between yes or no E6 Fail-message .........4110-7. Matrix examples.......................................................42

IM 12D7B2-E-H

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1. INTRODUCTION

1-1. ApplicationThe EXA SC200 transmitter is a 2-wire con-ductivity instrument intended to be used inindustrial installations in the field. For easymaintenance and operation it should belocated close to the sensors. The cable length is limited to 10 metre.It is powered from a remote low voltage DCpower supply through the 2-wire connec-tion.The EXA SC200 is compatible with mostcommercial available conductivity sensorsand fitting systems.The instrument is available in two versions:- A general purpose version for use in safe

areas.- An intrinsically safe version for use in

hazardous areas. The instrument can thenbe installed in Zone 1 with the sensors inZone 0 or Zone 1.

The micro-processor is used in this instru-ment for continuous loop diagnostics, flexi-ble on site commissioning and fine tuning byadvanced functions.

In general a conductivity loop can be set upfor different purposes:- To be part of a total process control sys-

tem.- To indicate dangerous limits of a process.- To monitor product quality.

1-2. Required components for conductivity measurement

A. a conductivity sensor ( also called con-ductivity cell) with integral temperaturesensor Ni-100 or Pt-1000.

B. a fitting for the above sensor with acces-sories.

C. a signal cable with or without extensionboxes etc.

D. the EXA SC200 2-wire transmitter withuniversal mounting accessory for wall,pipe or panel mounting.

E. a DC power supply (nominal 24 V DC)with cabling and optional zener barriers oran intrinsic safe power supply.

F. peripherals: e.g. strip-chart recorder,panel indicator, PID-controller

1-3. IdentificationThe instrument has an identification label,which is fixed to the front plate.This serves as a reference for the full modelcode, power supply voltage and serial num-ber. This label also carries authorised marksto certify compliance with the current regu-latory norms.

MODEL

SERIAL NO.

SUPPLY

IM 12D7B2-E-H

2. SPECIFICATIONS

2-1. General specificationsA. Intrinsic safety (model SC200S only)

- BASEEFA : Certified by and meets the requirementsof EEx [ia] ib IIC T4 of CENELECCertificate No.: 89C2379.

- FM : For IS CL1, DIV1, GP ABCD T3B for TA-30 to 70˚CT4 for TA-30 to 40˚CApproval report: J.I. 1Y1A7.AX

- CSA : For Ex[ia] Class 1, Div. 1, Groups Cand D, T4AApproval file: LR 102851-1

B. Indicating range : 0.055µS/cm to 2000 mS/cm at 25˚Creference temperature with cell-con-stants between 0.01 to 10 cm-1

C. Transmission signal : 4 - 20 mA DC; maximum load.550 Ω.D. Transmission range : User programmable to any range within

the indicating range with a maximum of60% zero suppression.A user programmable output table canbe set up in 21 steps.

E. Power supply- Model SC200G : 17 to 40 V DC, dependent on load.- Model SC200S : 17 to 31,5 V DC, powered from a certified

zener barrier or isolated power supplyF. Climatic condition

- Ambient temperature : -10 to +55 ˚C(10 to 130°F)- Storage temperature : -30 to +70 ˚C (-20 to 160°F)- Relative humidity : 10 to 90%- Weather protection : Rain and dust-tight to IP65 (NEMA 4X)- Interference protection : EMI Class B

RFI less than 2% at 5 V/m for20 MHz to 1 GHz.

G. Display method : Custom liquid crystal display.- Main display : 31/2digit, 12.5 mm high.- Message display : 6 alphanumeric characters, 7 mm.- Special fields : Flags for status indication.

: Units: µS/cm, mS/cm.: Key prompts: YES, NO, ^, >, ENT

H. Keys : 6 keys operated through the flexible win-dow with tactile feedback and one hid-den key behind the front cover.

I. Housing- Body material : Cast aluminium with chemical resistant

coating.- Window : Flexible poly carbonat.- Colours used : Moss green/ off-white.- Cable glands : Polyamide- Cable entries : Two glands PG 16 (1/2” NPT adapter for

US Model).Hose connection optional.

- Terminals : For maximum 2.5mm2 cable (cablefinishings preferred).

- Earth connection : For external ground.J. Mounting possibilities

- Bracket mounting : Two M6 bolts, 9 mm length.Wall, or pipe mounting by the optionalmounting kit, panel mounting by self tap-ping screws.

K. Shipping details- Dimensions : 162 x 178 x 115 mm

(6.5 x 7 x 4.5”)- Package : 290 x 225 x 170 mm

(11.5 x 8.9 x 6.7”)- Weight : approx. 2,5 kg (5 Ibs)

L. Safety and security- Data protection : Non volatile memory(EEPROM).- Data backup : All data is stored 3 times.- Interference test : according to IEC 801.- Power down : no effect, reset to measurement.- Operation : All 3 levels can be protected with a 3

digit passcode.

2

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2-2. Functional descriptionThe EXA SC200 is a real time micro-control-ler operated conductivity-analyzing system.It uses a dedicated micro-controller to con-trol all function necessary in such a system.The input and output functions are concen-trated in the analogue section of the instru-ment. Even these functions are operatedthrough special interfaces designed to givea minimum of interference problems to thedigital functions. A separation of function isstrictly executed.By using very low power components it ispossible to make a complete micro-compu-ter system work on less than 4 mA current.By using an EEPROM for essential informa-tion the operating parameters are fixed inmemory without the need for batteries. Thesupply-voltage is stabilized by regulators tothe internal supply system. Any voltagebetween 17 and 40 Volt is acceptable.The user-interface is limited to a basic set of6 keys accessible through the flexible win-dow cover.The software is designed with the user inmind. It uses a simple 3 layer set-up tocommunicate with the operator by givingmessages on the second line of the displayarea and indicating which keys are to bepressed in the display too.

The keys are scanned continuously and theactions are taken immediately. An extensivesystem of checking values and parametersis implemented.

The EXA SC200 operates just like a normal2-wire instrument but with additional func-tions. These extra functions are possible byusing a micro-controller at the heart of thesystem.- Continuous sensor polarisation checking

during measurement.- Automatic optimisation of measuring pulse

frequency and reference voltage.- Accurate temperature compensation by

non liner NaCI algorithm.- Simple output range adaptation making it

a versatile instrument.- A HOLD-function for the current output

signal.- Selection of temperature sensors.- Passcode protection.

Additionally YOKOGAWA designed the in-strument in such a way that an intrinsicallysafe version is available with the same featu-res and specifications. In fact the instrumentis only adapted slightly to fulfil the require-ments of CENELEC.

The instrument comes in 2 versions only:-A general purpose model.-An intrinsically safe model.

This makes it easy to set up the instrumenton site and valuable for large scale exchan-ges or emergency operations.

IM 12D7B2-E-H

3. INSTALLATION AND WIRING

3-1. Installation and dimensions3-1-1. Installation siteAs the transmitter is a rain-tight type, it canbe installed outdoors as well as indoors. Itshould, however, be installed as close aspossible to the sensors avoiding long cablelengths between sensors and transmitter.The certified version can be installed in Zone1.Select an installation site where:- mechanical vibrations and shocks are neg-

ligible;- no relay/power switches are in the direct

environment;- the transmitter is not mounted in direct

sunlight and severe weather conditions;- maintenance activities are possible (no

corrosive atmospheres).

The ambient temperature and humidityshould be the limits of the specifications.

3-1-2. Mounting methodsThe EXA SC200 transmitter has universalmounting possibilities:- panel mounting using selftapping screws;- surface mounting on a plate (by bolts from

the back);- wall mounting on a bracket (e.g. thick brick

wall);- pipe mounting using a bracket on a hori-

zontal or vertical pipe (maximum diameter50 mm);

Panel-mounting Surface mounting

Cut-out dimensions for panelmounting Dimensions

4

2 x M6 (bolts)

Unit: mm (inch)

162 (6.4)

115 (4.5)77

180

(7)

30 (1

.2)

Unit: mm (inch)

min. 203 (8)

min

. 229

(9)

172

(6.7

7)

154(6.06)

30 (1.18)

2x ø4

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Universal pipe/wall mounting

Wall mountingPipe mounting

(vertical)Pipe mounting

(horizontal)

2" I.D. pipe2" I.D. pipe

115

200

70

4x ø10

2x ø6.6

56

77

IM 12D7B2-E-H

3-2-4. Access to terminal and cableentry

1. To access terminals remove the frontcover of the EXA SC200 by releasing the4 captive screws.

2. Pull the sensor cable into connectionspace and connected the wires to theterminals as indicated by the numbers onthe wires. Make sure all connections arefirm and do not touch each other.

3. Screw the gland securely and tighten it tokeep out moisture. DO NOT use awrench to tighten the nut.

4. A hose connection can be used to guidethe cables coming from an immersion fit-ting through a protective plastic tubing tothe transmitter. This adaptor has to bebought separately.

3-2. Wiring of sensors

3-2-1. General precautionsGenerally, transmission of signals from theconductivity sensor is at a low voltage andhigh impedance level. Thus care must betaken to avoid interference.Before connecting the sensor cable to thetransmitter make sure the next conditionsare met:- the sensor cable is not to be mounted in

tracks together with high voltage and orpower switching cables;

- use only the standard conductivity cablewith a maximum length of 10 metre;

- mount the transmitter within the distanceof the cable.

NOTE: The outside earth terminal should be con-nected to site ground by a large area con-ductor (e.g. a flat earth strip) for best protec-tion against interference.

3-2-2. Additional precautions for instal-lations in hazardous areas

Make sure that the total of capacitancesandinductances connected to the input termi-nals of the EXA SC200 do not exceed thelimits given in the certificate.This sets a limitto the cable and extensions used.

The intrinsic safe version of the EXA SC200instrument can be erected in Zone 1.

The sensors can be installed in Zone 0 orZone 1 if a safety barrier according to thelimits given in the system certificate is used.

3-2-3. Grounding the liquidIn all circumstances, the sensor side of themeasuring loop is grounded to the measu-ring liquid through one of the electrode con-tacts in the conductivity cell. The supply andoutput signal are isolated to avoid uninten-tional ground loops.

6

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Range selection

3-2-5. Connecting diagram for sensors

2-Electrode system 4-Electrode system

TEMPERATURESENSOR

TEMPERATURESENSOR

CEL

C= 10/cm

C= 1/cm

C= 0.1/cm

C= 0.01/cm

CEL

e.g.Use cable WU40/LH...Max. recommended length 10 m Use Cells SC41 or SC42

Range selection* Use of 4-electrode

cell recommended

e.g.Use cable WU40/LH...Max. recommended length 10 m.Use Cells SC49

1 µS/cm 1 mS/cm 1 S/cm 1 µS/cm 1 mS/cm 1 S/cm

C= 10/cm

C= 1/cm

*

*

IM 12D7B2-E-H

3-3. Wiring of power supply3-3-1. General precautionsDo not activate the power supply yet.Firstmake sure that the DC-power supply isaccording to the specifications given.WARNING: DO NOT USE ALTERNATINGCURRENT OR MAINS POWER SUPPLY! !The cable leading to the distributor (powersupply) or safety barrier transports power toand output signal from the transmitter. Usea two conductor shielded cable with a sizeof at least 1.25 mm2 and an outside diame-ter of 9 to 15 mm. The cable gland suppliedwith the instrument accepts these diame-ters. The maximum length of the cable is2000 metre. This ensures the minimum ope-rating voltage for the instrument.

3-3-2. Additional precautions forinstallation in hazardous areas

1. Ensure that the total of capacitancesand inductances connected to the termi-nals of the EXA SC200 do not exceed thelimits given in the certificate of the safetybarrier or distributor.

2. The cable used should preferably have aBLUE colour or marking on the outside.

3. Grounding:• If the transmitter is mounted on a

grounded surface (e.g. a metal framefixed in the soil) the shield of the 2-wirecable may NOT be connected toground at the distributor.

• If the transmitter is mounted on a non-conducting surface (e.g. a brick wall) it isrecommended to ground the shield of the2-wire cable at the distributor end.

4. Installation for EEx ia (sensors in Zone 0or 1):

Generally, the distributor with input/outputisolation has no external earth connection.Ifthere is an earth connection on the distribu-tor and the external connection of the trans-mitter is connected to ”protective” earth, theshield of the 2-wire cable may NOT be con-nected to ”protective” earth at the distributortoo.

3-3-3. Access to terminal and cableentry

The terminal strip is accessed by removingthe cover from the transmitter as was des-cribed in § 3-2-4.Use the left-hand gland to insert the 2-wirecable to the transmitter.Connect the supply to the terminals marked+, - and G as is indicated in the figures onpages 9 & 10.

3-3-4. Power onAfter all connections are made and chec-ked, the power can be switched on from thedistributor. Observe the correct activation ofthe instrument at the display.If for any rea-son the display does not indicate a value,consult the trouble shooting section.

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Wiring diagrams for power supply

General purpose designConductivity transmitterEXA SC200G

NOTE:The outside earth terminal should be connected to site ground by a large areaconductor (e.g. a flat earth strip) for best protection against interference.

Sen

sor

Distributor

Output

Supply

Dependance of load to supply voltage

1200

1000

800

600

400

200

0 1718 20 24 40

Ohm

550

Supply voltage (V)

Load

res

ista

nce

(Ω)

IM 12D7B2-E-H

Wiring diagrams for hazardous areas

10

Intrinsically safe design(CELENEC standard EEX ib [ia] IIC T4)Conductivity transmitterEXA SC200S

EEx ibcertified safety

barrier Distributor

Out

put

Sen

sor

Elektronic currentLimiting barrierVmax: 31.5 Vlmax : 35 mAPmax: 0.66 W

Zener barrier withresistorVmax: 28 Vlmax : 93.3 mAPmax: 0.66 W

Protective earth

Safe area

Protective earth

Hazardous area Supply

Zone 0 of 1 Zone 1

Eex ibCertified distributor with

input/outputisolation

Out

put

Sen

sor

Shunt zener-barrier orsupply unit or isolated repeater Vmax: 22 VImax : 85 mA

Protective earth

Safe areaHazardous area

Sup

ply

Zone 0 of 1 Zone 1

Intrinsically safe design(CELENEC standard EEX ib [ia] IIC T4)Conductivity transmitterEXA SC200S

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4. COMMISSIONING

4-1. Operations overview

MAINTENANCEOperation by keysthrough the closed cover

CAL

DISPLAY

HOLD

Calibration

Show or fix additional values

Switching hold function on/off

5-1

5-2

5-3

Adjusting the output range

Activating the hold function

Temperature compensation

4-2

4-3

4-4

Fine tuning the performance 7

OUTPUT

SET HOLD

TEMPERATURE

SERVICE

COMMISSIONINGOperation by *-keywhen cover is removed

SERVICEOperation by codedentry from commissioning

Routine Use Chapter

Note: All levels can be protected by a 3 digit passcode. See §7-15.

IM 12D7B2-E-H

Remove cover by releasing 4 screws. Display will show * 0% Display will show *100%

12

4-2. Output range adjustment

1. Access output 2. Adjust low span value 3. Adjust high span value

OUTPUTSET HOLDTEMPERATURESERVICE

YES NO

YES NO

MODE

.

*

O U T P U TS E T H O L DT E M P .S E R V I C E

EN T

µS/cm

ENT


EN T

mS/cm

ENT

Access commissioning menu Adjust value for low spanSelect digit to adjustor decimal point and units

Adjust digit

Confirm adjusted valueENT

L*

Return to measurement

select output functionSelect OUTPUT

YES

NOTE:If the output is commissioned to be via atable this whole item will be skipped! Defaultis a linear range.

LAdjust value for high spanSelect digit to adjustor decimal point units

Adjust digit


L

L

MODE

ESCAPE TO MEASURE can be used at any stage to abort operation. WARNING: If the HOLD function is activated the instrument returns with the question HOLD (flashing);answer YES or NO or MODE again to return to measurement.

MODE

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13

1. What is the output range?The display will always show the full range ofthe instrument from 0-2000 mS/cm.Maximum resolution is assured by autorang-ing, where the position of the decimal pointand the measuring units (microSiemens/-milliSiemens) are moved to best fit the actu-al value.

For control or recording the current outputcan be ranged to a specific part of the totalmeasuring span. When selecting themeasuring range care must be taken to usethe appropriate conductivity cell. For anygiven cell constant there is a defined rangeof operation which should not be exceeded.

From the factory the instrument has a linearoutput range 0-1 mS/cm in combinationwith a cell constant C=0.1 cm-1.

Other linear ranges can be programmed inthis routine. It is also possible to programnon linear output ranges for specific applica-tions. These are programmed in the servicelevel, see sections 7-5 and 7-6.

2. Programming a linear output rangeA linear output range is programmed byentering two values:- 0% the conductivity at the start of the

output range which correspondsto 4 mA

- 100% the conductivity at the end of theoutput range which corresponds to20 mA.

When programming a range which does notstart at zero conductivity, take care torespect the minimum value correspondingto 60% of the maximum value.

3. ExampleThe EXA SC200 has an output table whichcan be programmed to give any non-linearoutput characteristic. Activation of this tableis described in §7-5. Once the table is acti-vated the linear OUTPUT routine will no lon-ger have any effect and will not be accessi-ble in the commissioning menu.Programming of the 21 step table is descri-bed in § 7-6.

Non-linear outputs are commonly used formeasurements in pure water where highresolution is required over a small rangecombined with trend indication over a largerrange. Common forms of output for theseapplications are given in §7-17.The non-linear output can also be used tofollow a concentration curve for a specificproduct. Care must be taken to ensure thatthe temperature compensation is also setup for the measured fluid under representa-tive conditions. It should also be noted thatconductivity measurements are not specific,so it can be influenced by impurities presentor changes in the fluid composition.

4. Other possibilitiesProgramming a percent by weight indicationon the second display line §7-13

4-2. Output range adjustment

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14

*HOLD = Set HOLD function Display shows actual status.*H.OFF = HOLD not active*H.ON = HOLD activated

Displa`y shows current setting

4-3. Set up HOLD function

1. Access HOLD routine 2. Activate HOLD function 3. Adjust value to hold


YES NO

YES NO

MODE

.

*


YES NO

YES NO

MODE

.

*


EN T

ENT

HOLD

.

Access commissioning menu

SELECT choice

*

Select SET HOLDMove pointer to SET HOLD

NO

YES

Activate (de-activate) HOLDChange setting

Conform setting

NO

YES

Select HOLD fixed or lastChange selection

Confirm selection

NO

YES

*H.FIX = Hold fixed value*H.LST = Hold last value

Adjust fixed valueSelect digit to adjust

Adjust value of digit

Accept value

Return to measurement

ENT

L

L

MODE

ESCAPE TO MEASURE can be used at any stage to abort operation. WARNING: If the HOLD function is activated the instrument returns with the question HOLD (flashing);answer YES or NO or MODE again to return to measurement.MODE

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1. What is HOLD?HOLD is a function freezing the output sig-nal temporary, during normal maintenance,preventing all sorts of alarming situations tooccur.Two possibilities are generally used:

a .Keeping the output at the LAST value justbefore the start of maintenance. This canonly be used when a recorder is connec-ted.

b. Keep the output at a preset FIXED valuewhich will not cause any of the alarms togo off or any controlling action to betaken. This is the preferred situation whendealing with Conductivity-control sys-tems.

2. How does it work?The HOLD-function has to be activated fromthe *-menu before it can be used.

The EXA SC200 will keep the output frozenduring the following events:- Access to the *-menu.- Access to the calibration mode.- Switching it from the MODE-menu.

HOLD is signalled in the display by a specialfield.

The operator is prompted to switch HOLDon or off before returning to normal mea-surement.

3. ExampleIn a storage tank the concentration of sodi-um hydroxide (caustic soda) has to be keptat 5% . The mixing process is controlled bya conductivity transmitter and electro-mag-netic valves.During maintenance of the conductivity cellor the transmitter the HOLD function is acti-vated to keep the mixing process from was-ting precious chemicals to the sewer.The HOLD function is set for a fixed outputso that the dosing valves will not be activa-ted.

4. Time outHold will be de-activated after 20 minutes ifno key is pressed. To cancel this functionsee 7-8.

4-3. Set up HOLD function


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TEMP = Temperature compensation function NaCl = Automatic temperature compensation The setting of the temperature coefficient is doneby adjusting a conductivity value, at process tem-perature, to the conductivity value that was meas-ured at reference temperature

4-4.Temperature compensation

1. Access temperaturecompensation routine

2. Select automatic NaCltemperature compensation

3 Select temperature coefficientcompensation


YES NO

YES NO

MODE *


YES NO

YES NO

MODE *


EN T

ENT

TEMP. MAN

. .

mS/cm

Access the maintenance menu

Select temperature compensationfunction

*

Select temperature compensationroutineMove pointer to TEMP

NO

YES

Select automatic compensationChange displayed selection

Confirm selection

NO

YES

NOTE:1. If NaCl is chosen the temperature compensa-

tion will be according to NaCI solutions.2. If *NaCl and *T.C. do not appear, this indicates

that Matrix compensation is selected in servicecode 13.

Adjustment of the conductivity value Select digit to adjust

Adjust manual temperature


L

L

Error E2 indicates that the temperature coefficientis less than-10%/°C or more than +10%/°C.

NOTE:Direct setting of the compensation factor is possible.Refer to §7-12.

MODE

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1. Why is temperature compensationnecessary?

The conductivity of a solution is very strong-ly influenced by temperature. Typically forevery 1°C change in temperature the solu-tion conductivity will change by approxima-tely 2%.

The effect of temperature varies from one-solution to another and is determined byseveral factors: solution composition,con-centration and temperature range. In verypure water the temperature influence increa-ses dramatically with increasing purety toapproximately 6%/°C.

A coefficient (a) is used to express theamount of temperature influence in % chan-ge in conductivity/°C.In almost all applications this temperatureinfluence must be compensated before theconductivity reading can be interpreted as ameasure of concentration or purity.

2. Automatic temperature compensa-tion with EXA SC200

From the factory EXA SC200 instrumentsare calibrated with a general temperature-compensation function based on a sodium-chloride salt solution. This is suitable formany applications and is compatible withthe compensation functions of typical labo-ratory or portable instruments.

As conductivity decreases into the range ofpure water the instrument will follow thenon-linear compensation function of neutralNaCl solutions. In the high conductivityregion the effect of temperature decreasesand the compensation factor is decreasedtoo. In these extreme regions the tempera-ture compensation factor is calculated witha square equation.

A temperature compensation factor is de-rived from the following equation:

α = Temperature compensation factor (in

%/°C)

T = Measured temperature (°C)

Kt = Conductivity at T

Tref = Reference temperature (25°C)

Kref = Conductivity at Tref

3. Manual setting of temperature com-pensation with EXA SC200

If the general compensation function isfound to be inaccurate for the sample inquestion, the instrument can be set manual-ly for a linear factor on site to match theapplication.

The procedure is as follows:1. Take a representative sample of the pro-

cess liquid during operation.2. Heat or cool this sample to the reference

temperature of the instrument (usually25°C). Note: see §7-4.

3. Measure the conductivity of the solutionwith the SC200 and note the reading ofthe display.

4. Bring the sample to the typical processtemperature. (Check the temperature withthe display routine.)

5. Adjust the reading of the display to thepreviously noted value at the referencetemperature.

6. Check that the temperature compensa-tion factor has been changed (from thedisplay routine).

7. Insert the conductivity cell into the pro-cess again

4. Other possibilitiesManual temperature coefficient §7-12.

4-4. Temperature compensation

Kt - Kref x 100α = XT - Tref x Kref

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4-5. Sensor selection and diagnostics

4-5-1. General remarksThe EXA SC200 continuous sensor diagnos-tics can lead to the indication of faults dueto the fouling of the connected sensor. Thefault will be indicated with a signal field onthe display and (if activated) by a 22 mA sig-nal. The selection of the correct conductivitycell with the suitable cell constant is explai-ned in the next section.

4-5-2. Selecting a conductivity cellFirst select the range limits for the EXA in-strument.For conductivity values below 1 µS/cm theonly choice is a cell with cellconstant 0.01cm-1. From 1 µs/cm up to 10 mS/cm a cell-with cellconstant 0.1 cm-1 can be used. Acellconstant of 1 cm-1 is used between 10µS/cm up to 100 mS/cm. The cell with cell-constant 10 cm-1 is used from 100 µS/cm to1 S/cm. All these values refer to the actualmeasured values at the operating tempera-ture.Above 20 mS/cm with C=1 cm-1 and 200mS/cm with C=10 cm-1 4-electrode cellsare advised.

Yokogawa delivers cells from a choice ofchemically resistant materials like stainlesssteel, epoxy resin, PTFE and PVDF.

The cell determines the principle used tomeasure the conductivity: there is a distinc-tion between 2-electrodes and 4-electrodescells.The selection of 2 or 4 electrode measuringprinciple is from the service level §7-9.

4-5-3. Selecting a different cell-con-stantThe EXA SC200 can be programmed to ac-cept any cell with a cell-constant between0.01 and 50/cm. The adjustment of the cell-constant must be executed from the servicelevel §7-7.

4-5-4. Integral temperature sensorThe factory setting for the temperature sen-sor is a Pt-1000 element. To get a differenttemperature setting the service level settingat § 7-4 is used.A separate temperature sensor can be con-nected, if no integral temperature element ispresent in the conductivity cell.Choose a Ni-100, NTC or Pt-1000 sensorto get the correct temperature reading.

4-5-5. Sensor diagnostics and related-error messages

The check for polarisation of the electrodesis only working correctly when the cell-con-stant has been chosen to match the measu-ring range. The check is automaticallyswitched off when the 4-electrode measu-ring principle is selected. The check canmanually be switched on or off: refer to §7-14. The factory setting for the polarisa-tion check is off.

18

IM 12D7B2-E-H

19

IM 12D7B2-E-H

20

CALIB = Calibration

START = Start calibration CAL.END = End of calibration session

5. MAINTENANCE5-1. Calibration

1. Access calibration routine 2. Adjust value 3. End calibration

M E A S U R EC A LD I S P L AY.H O L D

YES NO

YES NO

MODE

µS/cmMODE

.


YES NO

ENT

µS/cmMODE


YES NO

YES NO

MODE

µS/cmMODE

.

Access maintenance mode

Select calibration

Select manual calibrationMove pointer to display

NO

YES

End calibrationEnd calibration and return to measurement

Continue routine to calibrate secondpoint (repeat step 2)

YES

NO

MODE Conform start of adjustmentYES

Select digit to adjust

Adjust value

Conform adjusted valueENT

L

L

Adjust process value to previously determinedvalue (e.g. from hand-held conductivity-meter)

Error E3 indicates that the calibration value isdeviating more than 20% from the originally meas-ured value.


MODE

IM 12D7B2-E-H

21

1. When is calibration necessary?Calibration of conductivity instruments is notnormally required since conductivity cells aremanufactured within controlled tolerancesand do not alter in use.

If the cell has been severely fouled or sub-ject to abrasion (possibly during cleaning) itmay be necessary to calibrate.

Alternatively calibration may be carried outwith a simulator to check the electronicsonly.

2. How is calibration done?Calibration is carried out by measuring asolution which has a known conductivityand adjusting the instrument to show thecorrect conductivity value.

Calibration solutions can be made up in thelaboratory. A solution of salt is made withprecise concentration. Temperature is stabi-lised to the reference temperature of the in-strument (usually 25°C). The conductivity ofthe solution is taken from tables.

Alternatively the instrument may be calibra-ted in an unspecified solution against astandard instrument. Here care should betaken to make measurement at the refe-rence temperature since differences in thetype of temperature compensation of theinstruments may cause an error.

3. Typical calibration solutionsThe table below shows typical conductivityvalues for solutions which may be made upin the laboratory.

Table for NaCI at 25°C

5-1. Calibration

% weight mg/kg Conductivity

00.001 10 021.40 µS/cm00.003 30 064.00 µS/cm00.005 50 106.00 µS/cm00.01 100 210.00 µS/cm00.03 300 617.00 µS/cm00.05 500 001.03 mS/cm00.1 1000 001.99 mS/cm00.3 3000 005.69 mS/cm00.5 5000 009.48 mS/cm01 10000 017.60 mS/cm03 30000 048.60 mS/cm05 50000 081.00 mS/cm10 100000 140.00 mS/cm


IM 12D7B2-E-H

22

5-2. Selecting a value to display

DISP = DISPLAY routine

The second line of the display will show the possi-bilities

The second line of the display will show the possi-bilities

1. Access display routine 2. Read data 3. Reprogram data display


YES NO

YES NO

MODE

MODE


YES NO

YES NO

MODE

MODE

.M E A S U R EC A LD I S P L AY.H O L D

YES NO

YES NO

MODE

MODE

.


Select Display routine

Select displayMove pointer to DISPLAY

NO

YES

Read dataTo read values only

Parameter Unit- Temperature ˚C/˚F- Output signall mA- % by weight %

C.C - Cell constant cm-1T.R. - Reference

temperature ˚C/˚FNaCl/jjj - TemperatureT.C Compensation coefficient

standard/manual%/˚C

REL - software release

Return to measure

NO

MODE

Reprogram data displayMove to desired value for display

Parameter Unit- Temperature ˚C/˚F- Output signal mA- % by weight %

C.C - Cell constant cm-1

T.R. - Reference temperature ˚C/˚F

NaCl/jjj - TemperatureT.C Compensation coefficient

standard/manual%/˚C

REL - software release

To select a value for permanent dis-play during measurement

NO

YES

MODE

MODE

IM 12D7B2-E-H

23

1. What is the display routine?The second line in the display is intended tobe used to:- Show actual status- Show messages- Show errors

When delivered from the factory theEXASC200 shows the temperature on thesecond line.You can make the instrument show a diffe-rent parameter on the second line by selec-ting it from the list at right.

2. What can you read?Temperature is an actual value.Output is an actual value.Percent by weight is an actual value.Cell constant is programmed.Reference temperature is programmed.NaCl or temperature coefficient is program-med.

The choice of temperature units is donefrom the Service level.

Error messages have priority over othermessages.

Note: Percent by weight is only visible whenactivated from the service level §7-13.

3. ExampleTo check the value of the output signal(4...20 mA) it is displayed on the secondline.

Measuring range 0...100 µS/cmOutput signal 4...20 mA

Process value 60 µS/cmOutput value 13.6 mA

When the second line is changed to displayoutput the current signal is visible all thetime.

Whenever HOLD is activated the value onthe display is frozen to the programmedvalue (using the FIXED setting).Pressing MODE will take you back tomeasuring and the temperature will showagain.

5-2. Selecting a value to display


IM 12D7B2-E-H

24

5-3. Use of HOLD function

HOLD = HOLD output function

Display will blink HOLD and YES/NO

1. Access hold 2. Switch hold on/off


YES NO

YES NO

MODE

MODE


YES NO

YES NO

MODE

MODEHOLD


Select HOLD functionMove pointer to HOLD

Select HOLD functionSelect HOLD

NO

NO

Switch hold OFF

Switch hold ON

NO

YES

MODE

NOTE: This function can only be used if activatedduring commissioning (see chapter 4-3).

HOLD in left top of display is switched

MODE

IM 12D7B2-E-H

25

1. What is HOLD?Hold is a function which freezes the outputsignal temporarily, it is normally used duringmaintenance when the cell is removed fromthe measured solution to prevent unwantedcontroller reaction.

The HOLD function must be commissionedfrom the programming menu before it canbe switched on or off. See commissioningthe hold function for more details.

Note: AUTO RETURN will switch off HOLD after20 minutes, see § 7-8.

2. How does it work?From this level the HOLD function can onlybe switched ON or OFF.HOLD is switched on when you press YESwhen HOLD and YES/NO are blinking.When you press NO hold will be switchedoffA flag is kept in memory and an indication ismade in the upper left corner of the displayfield.

The HOLD function only influences the out-put signal, no other functions are influenced.

The operator is prompted to switch HOLDon or off after having performed a mainte-nance function.

3. ExampleDuring the transfer of cleaning liquid into abatch reactor with a conductivity-controlsystem, the HOLD function is switched ONto prevent the controlling instruments fromrunning wild.After cleaning has ceased and the newbatch has been started HOLD is switchedOFF again and conductivity control resu-mes.

5-3. Use of HOLD function

IM 12D7B2-E-H

6-1. IntroductionThe EXA SC200 microprocessor basedconductivity analyser continuously monitorsthe condition of all key components of themeasuring system to ensure that measure-ment is dependable. If a fault is detectedthis is immediately signalled. Errors areshown on the display with a code.The following table shows the errors whichcan be detected and gives information tohelp locate the fault or identify the error.Faults detected whilst the instrument is online can also be signalled by a (temporary)high output signal (22 mA).

6-2. Self diagnostics of the conductivitycell

During measurement the instrument adjuststhe measuring frequency to give the bestconditions for the actual value being meas-ured. At low conductivity there is risk oferror due to capacitive effects in the cableand cell. These are reduced by using a lowmeasuring frequency. At high conductivitythese capacitive effects become negliableand errors are more likely to be caused bypolarisation or fouling of the cell. Theseerrors are reduced by increasing the measu-ring frequency.

At all values the instrument checks the sig-nal from the cell to search for distortionwhich is typical of capacitive or polarisationerrors. If there is a problem with the installa-tion or the cell becomes fouled this will trig-ger an error message on the display possi-bly accompanied by a fault signal through a(temporary) high output current (22 mA).

6-3. Self diagnostics of the temperaturesensor

The temperature sensor, which is normallybuilt into the conductivity cell, is checked todetect damage or faulty connections.

NOTE: A temperature fault may be caused byincorrect programming of the temperatureelement!

6-4. Self diagnostics of the electronicsThe microprocessor operation is checkedby a watchdog which initiates an electronicreset if the normal function suffers severeinterference. During reset the instrumentchecks the program and all stored data. If afault is then detected an alarm is given.

6-5. Checking during operationWhenever the instrument is being program-med or calibrated, data is checked and anerror is shown when appropriate.Should this occur the new data is rejectedand the instrument continues to work withthe previous settings.

26

6. TROUBLE SHOOTING

IM 12D7B2-E-H

27

6-6. Error messages and explanation

Code Error description Possible cause Suggested remedyE1* Faulty signal from conductivity cell Polarisation Check cell is correct for range

Cell is fouled Clean cell

E2 Wrong temperature coefficient during Incorrect data entered Repeat temperature calibrationcalibration

E3 Calibration out of limits Calibration value deviates more than Check cell, connections or reference20%

E5* Conductivity too high Measurement is out of range Check cell range, reprogram rangeE6* Conductivity too low Measurement is out of range Check cell range, reprogram rangeE7* Temperature too high Wrong temperature sensor selected Program sensor type

Fault in connections Check connectionsE8* Temperature too low Wrong temperature sensor selected Program sensor type

Fault in connections Check connectionsE10* EEPROM write failure Fault in electronics Call yourYOKOGAWA service

organisationE15 Temperature correction Fault in cable or wrong Check connections or program

outside limits (> 5Ω) temperature sensor selected correct sensor typeE17 Output span too small 0% range value set too high Program value <60% of high range

E18 Output table makes no sense Table changes from ascending to Check programming of tabledescending or vice versa

E19 Programmed value not accepted Values not acceptable Reprogram with new values

E20* Data lost Data, including initial setting, lost Call your YOKOGAWA serviceorganisation

* These errors will trigger the FAIL-status.

IM 12D7B2-E-H

7. SERVICE MODE

7-1. IntroductionGenerally speaking their is no necessity toadjust the settings of the service section Allparameters are pre-programmed to values(so-called defaults) enabling you to startworking immediately.

The advanced functions available throughthis section are only needed in some speci-fic applications. This fine-tuning of the in-strument gives a superior performance overconventional 2-wire instruments.

If a function has to be adjusted it is called upwith the code mentioned. Having selectedthe code then give you the possibility toeither activate or adjust the values for thisfunction. After this you will return to theentry point to make other adjustments or goback to the measuring status.

If errors are made during the programmingprocess, these will be indicated, no actionwill be taken and you can start the program-ming again.

28

Code Routine Use Chapter

01 Temperature sensors and units Select sensor type 7-3Select °C or °F

02 Reference temperature Adjust value 7-403 Output table or linear Select which to use 7-504 Program output table Set values in table 7-605 Cell constant Adjust cell-constant 7-7 +10-106 Auto return function Switch on or off 7-807 Measuring principle Select 2 or 4 electrode 7-908 Temperature adjust Correct cable error 7-1009 Signal errors or output Switch on or off 7-1110 Temperature compensation factor Adjust factor 7-1211 %-indication on second Switch on or off and 7-13

display line Set values12 Polarisation check Switch on or off 7-1413 Matrix compensation Select 5x5 matrix compensation 10-214 Matrix temperature Set temperatures for user matrix 10-3

compensation range15-19 Matrix data Set data for user matrix 10-420 “Soft”/“hard” fail situation Select “soft” or “hard” fail 10-5

message per fail code21 E6-fail message Switch on or off 10-633 Passcode activation Protecting levels 7-1555 Restore defaults Erase values 7-16

IM 12D7B2-E-H

29


7-2. Access to service settings

*SERV = Service settings

Display will show *CODE Display shows current settingValues adjusted access to individual routinedescription

1. Access service 2. Enter code to selectrequired function

3. Adjust setting(see individual routines)


YES NO

YES NO

MODE *


EN T

ENT


EN T

ENT

.

.

Access commissioning menu

Select SERVICE

*

Select service functionMove pointer to service

NO

YES

Enter access code to select routineSelect digit to adjust

Adjust code for entry

Confirm choiceENT

LL

Adjust settingsSelect digit to adjust

Adjust value


L

L

Return to measure

MODE

MODE

X.X0. Temperature sensor = Pt-10001. Tempersture sensor = Ni-1002. NTC sensor.0 Temperature displayed in ˚C.1 Temperature displayed in ˚F

IM 12D7B2-E-H

30

7-3. Temperature sensors and unitsACCESS-CODE: 01 (see § 7-2)DISPLAY : *T.CODE

Adjustment (X.X)

7-4. Reference temperatureACCESS-CODE : 02 (see § 7-2)DISPLAY : *T.R. ˚C or *T.R. ˚F

Adjustment : Adjust the value for thereference temperatureused in the calculations.Normally this value will be25˚C.

Explanation:The code for the temperature units influen-ces the temperature indication on the dis-play only. Default value is ˚C.The indication here determines which tem-perature sensor is connected to the instru-ment. Check what sensor will be used inyour plant and set the correct number for it.Default value is Pt-1000 for Yokogawa sen-sors, type SC42-.....

Default: ˚C

Explanation:All measured values are compensated fortemperature to refer to comparable valuesat 25˚C. This temperature is easily producedat laboratory conditions and most literaturedata use this temperature. In exceptionalcases it is possible to use a different refe-rence temperature in combination with aprogrammed temperature coefficient (e.g.Sulfuric acid measurement).

Default: 25˚C

7-5 Output code selectionACCESS-CODE : 03 (see § 7-2 )DISPLAY : *TABLE

Adjustment : 0=Linear range only1=Output table with 20steps

Explanation:As a default a linear output is set and only0% and 100% can be adjusted from thecommissioning output function.When an output table is programmed bysetting a 1, the table can be programmed atCODE 04.Otherwise CODE 04 will have no effect. Seethe entry at the next CODE.

IM 12D7B2-E-H

31

7-6. Output table for non-linear rangeACCESS-CODE : 04 (see §7-2)DISPLAY : 0% to 100%

Adjustment : A 21 step table can beprogrammed from thisentry ONLY IF it was setin the previous CODE 03.It is possible to set up abi-linear, semi-logarith-mic or hyperbolic scaleto cope with retro fittingon existing installations.Also linear output to con-centration related curvescan be programmed.

Explanation:First you will be presented with the questionYES/NO to give the opportunity to skip valu-es from the table. To get a 10 step table youwould skip every other value and only ans-wer YES to enter a value. The instrumentuses interpolation between entered values.Press NO to skip values. Press YES toadjust value. Now adjust the value by pres-sing > and ^.The units can be adjusted as well as thedecimal point position.Examples are mentioned in §7-17.Other possibilities: programming ”% byweight” indication on second display line:refer to §7-13.

Percentage of mA-output range versuspercentage of conductivity range.

Examples:A = bilinearB = hyperbolic (2 decades)C = logarithmic (2 decades)D =linear

NOTE:Curves are not selectable, but can be pro-grammed from the tables at right.

Example of output tables

bi-lin = bi-lineair over 2 decadeslog 2 = logarithmic over 2 decadeslog 3 = logarithmic over 3 decadeshyp 2 = hyperbolic over 2 decadeshyp 3 = hyperbolic over 3 decades

NOTE:Multiply the values from the table withappropriate factors to get the end-scalevalue you want.

Special concentration tables can be pro-grammed by the user.

mA-output range

% of conductivity range

Output bi-lin log 2 log 3 hyp 2 hyp 3

0% 0.0 1.0 0.10 1.00 0.105% 1.0 1.3 0.14 1.20 0.2710% 2.0 1.6 0.20 1.82 0.4315% 3.0 2.0 0.28 1.90 0.6120% 4.0 2.5 0.40 2.00 0.8325% 5.0 3.2 0.56 3.75 1.1030% 6.0 4.0 0.79 4.80 1.3635% 7.0 5.0 1.12 5.92 1.6840% 8.0 6.3 1.58 7.00 2.0545% 9.0 7.9 2.24 8.31 2.4950% 10.0 10.0 3.16 10.00 3.0055% 20.0 12.6 4.47 11.85 3.6660% 30.0 15.8 6.31 14.00 4.3365% 40.0 20.0 8.91 16.65 5.2270% 50.0 25.1 12.6 19.50 6.8075% 60.0 31.6 17.8 23.80 8.2580% 70.0 39.8 25.1 29.55 11.085% 80.0 50.1 35.5 36.70 14.890% 90.0 63.1 50.1 48.50 21.895% 100.0 79.4 70.8 68.60 36.5100% 110.0 100.0 100.0 100.00 100.0

X

0 OFF1 ON

IM 12D7B2-E-H

32

7-7. Cell constant adjustmentACCESS-CODE : 05 (see §7-2)DISPLAY : *CELL.C

Adjustment : Adjust the value to thecell-constant used withyour instrument.Values between 0.01 and50/cm can be program-med.

Explanation:Every conductivity cell has a cell-constant,which can be indicated on the outside of thebody. Sometimes the cell-constant can beindicated in the type-number of the sensor.Yokogawa produces several models withcell-constants of 0.01, 0. 1, 1 and 10/cm.For accurate measurements the cell-con-stant can be determined in a laboratory test.

Default: 0.1 cm-l

7-8. Auto return functionACCESS-CODE : 06 (see §7-2)DISPLAY : *RET

Adjustment: X

ExplanationAs a safeguard against long maintenancejobs or inadvertently pushing a button it ispossible to let the system return to its nor-mal function of measurement when no keysare pushed for 10 minutes.

Default: Auto return on

7-9. Measuring principleACCESS-CODE : 07 (see §7-2)DISPLAY :*4ELEC

Adjustment : Select the measuringprinciple of the transmit-ter.

X

0 2-electrode principle1 4-electrode principleAutomatic return to measure after 10

minutes.

Explanation:Select the principle to cooperate with themeasuring sensor.The conductivity cell determines which prin-ciple can be used. The 4-electrode principle is used for thehigh conductivity values in general.

Default: 2-electrode principle

X.X0 OFF1 ON = 22 mA steady signal on

fault.2 ON = 22 mA pulse during

30s at start of faultthen normal output.

IM 12D7B2-E-H

33

7-10. Temperature sensor adjustmentACCESS-CODE :08 (see § 7-2)DISPLAY :*T.ADJ

Adjustment :Adjust the value of theindicated temperature(°C/°F) to that of theactual temperature.

Explanation:The temperature measurement is a two wireresistance measurement. In this kind ofmeasurement the length of the connectingcable can influence the accuracy of the tem-perature indication. To compensate for theextra resistance of the cable up to 5Ω canbe calibrated. Connect the correct tempera-ture sensor to the EXA instrument and insertit in a stable temperature bath of a knownvalue.Check the temperature indicated at this set-ting in °C or °F and adjust the value ifnecessary.Now the EXA transmitter has been calibra-ted to compensate for the cable resistance.

7-11. Signalling of fail conditionACCESS-CODE : 09 (see §7-2)DISPLAY : *BURN

Adjustment : X.X

Explanation:Besides an indication at the display in thefield, sometimes an indication of errors in thecontrol room is also necessary. This is possi-ble by sending a special signal over the 2-wire connection to the receiving instrument.A signal of 22 mA is used, because it is out-side the normal analogue range of 4 to 20mA. If at the receiving end an alarm is set tothe value represented by 22 mA, it is obviousthat the proper action can be taken from thecontrol room too. The signal uses the sameconvention as used in thermocouple indica-tions for detecting break of the sensor (burn-out).

Default: 0 = OFF

7-12. Temperature compensationcoefficient adjustment

ACCESS-CODE : 10 (see § 7-2)DISPLAY : *T.C.

Adjustment : Adjust the value of themanually set compensa-tion factor

NOTE:Access to this routine is only possible whenmanually set temperature compensationfactor (α) is selected in §4-4.

Explanation:In addition to the procedure described in§4-4 it is possible to adjust the compenstionfactor directly. If the compensation factor ofthe sample liquid is known from laboratoryexperiments or has been previously determi-ned, it can be introduced here.Adjust the value between -10.00 to -10.00% per °C. In combination with the referencetemperature setting at §7-4 a linear com-pensation function is obtained, suitable forall kind of chemical solutions.

Kt - Kref x 100α = XT - Tref x Kref

Default: skipped, compensation for NaCIis automatic.

X0 OFF1 ON

IM 12D7B2-E-H

34

7-13. Percent by weight indication onsecond display line

ACCESS-CODE : 11 (see § 7-2)DISPLAY : *%

Adjustment:(X)

Select the possibility to display % by weighton the second display line. When %indication is activated (Select 1) the displayrange can be adjusted:*0%: Adjust low span display value*100% Adjust high span display value

Explanation:In case a conductivity measurement is usedfor concentration monitoring it can be con-venient to link the measured conductivityvalue to a % by weight concentration value.A linear concentration indication in % units isprogrammed by entering two values.- X in 3 digits corresponds to 0% of theoutput value (= 4 mA)

- Y in 3 digits corresponds to 100% of theoutput value (= 20 mA)

Example:0% output is 93.0% by weight

100% output is 99.0% by weight

The instrument uses interpolation betweenthe entered values. As the relation betweenpercent by weight concentration and con-ductivity is not linear in most cases, the pos-sibility to linearize the output to concentra-tion units can be used. Refer to §7-5 and§7-6. The instrument becomes a concentra-tion meter by output function and (second)display (line) based on a conductivity mea-surement.

Default: OFF

7-14. Polarisation checkACCESS-CODE : 12 (see §7-2)DISPLAY : *POL.CK

Adjustment: (X)

Generation of the fault E1 can be switchedoff.

Explanation:The EXA SC200 normally checks the signalfrom the cell to search for distortion typicalof capacitive or polarisation errors. If there isa problem with the installation or the cellbecomes fouled this will trigger the E1 faultsignal.In some installations this error detecting cancause unwanted signals during operation.Then the possibility to disable this check willbe used.

Note: When 4-electrode measurement ischosen this checking is not performed.

Default: OFF

X0 OFF1 ON

IM 12D7B2-E-H

35

7-15. Passcode protection by three digitcode

ACCESS-CODE : 33 (see § 7-2)DISPLAY : *PASS

Adjustment(X.X.X)

0.X.X Protection on Maintenance level inactive

X.0.X. Protection on Commissioning level inactive

X.X.0 Protection on Service level inactive

#.X.X Protection on Maintenance level activated

X.#.X Protection on Commissioning level activated

X.X.# Protection on Service level activated

Note: # can be a digit from 1 to 9, and it willgive a protection according to the schema-tic below of the programmed level.0 = No passcode 5 = Passcode is 1231 = Passcode is 111 6 = Passcode is 9572 = Passcode is 333 7 = Passcode is 3313 = Passcode is 777 8 = Passcode is 5464 = Passcode is 888 9 = Passcode is 847

Explanation:In some cases a protection of operationlevel is wanted. In this way unauthorizedaccess to any of the 3 levels can be blockedby a simple passcode. When a passcode isselected for an operation level, access tothat level can only be obtained after ente-ring the passcode. The display will show amessage *PASS* to indicate the entry of thepasscode.

NOTE:For the Maintenance and Commissioninglevel the passcode entry is always requestedwhen entering from the measure mode.- For the Service level the passcode entry is

requested after pushing the YES-key.- When the Service level protection is activa-

ted, the passcode cannot be changed byunauthorized persons.

Default: 0.0.0.No Passcode protection.

7-16. Restore default settingACCESS-CODE : 55 (see §7-2)DISPLAY : ERASE

Adjustment: YES Erase all program-med values andreplace them bydefaults.

NO Keep all program-med values as befo-re.

Explanation:This entry is provided to make it possible tostart from the default values given byYokogawa and thus erase all previously pro-grammed information.

WARNING:Do not use this code without proper authori-ty as all settings and programmed functionswill be lost!!

WARNING

Do not enter service codes that arenot mentioned in this booklet.

11

12

14

13

17

15

16

G

- +

IM 12D7B2-E-H

36

8. CLASSIFICATION

1 conductivity sensor with integral SC41-SP34temperature sensor such as (but SC49-FP08not limited to) SC41-SP24

SC41-EP14SC41-EP04

These are all passive sensor to be regarded as "simple apparatus"i.e. devices which coply with clause 1.3 of EN 50014.

SC 200 SVout = 14.4 V max.Iout = 72.8 mA max.C ext = 1300 nF maxL ext = 8.0 mH max.

BASEEFA Nr. Ex 89C2379

connecting cablessuch as (but not limited to):WU40-LH18 WU40-LH2WU40-LH5

Certified Barrier with electronic current limitation and the fllowing characteristics:V max. out = 31.5 V, Imax. out = 35 mA, P max. out = 1.1 Wtype : Yokogawa Bard 400 (BASEEFA Cert. Ex 84B2257x)

Any shunt zenerdiode safety barrier certified by BASEEFA or any EEC approeved certification body to [EEx ia] II C or [EEx ib] ii C where theoutput current is limited by a resistor "R" directly in the output line such as that Imax.out = Vmax.out/R and not exceeding the following char-acteristics:Vmax.out = 28 V; Imax.out = 93.3 mA and Pmax.out = 8.66 W.such as (but not limited to):type: MTL 728

MTL 788 (BASEEFA Cert. Ex 832452)MTL 788 RStahl 8981/31-280/085/00 (P.T.B. Cert. Ex-78/2007X)

any shunt zenerdiode safety barrier or supply unit or isolated repeater certified by BASEEFA or any EEC approevd certification body to [EEx ib]ii C or [EEx ib] ii C where the output current is limited in a different way and not exceeding the following characteristics:Vmax.out = 22 V and Imax.out = 85 mAsuch as (but noy limited to):type: Camille Bauer Sineax 84-2B1-511

Sineax 89-2B1-511 (P.T.B. Cert. Ex-81/2044X)

NON HAZARDOUS AREA

or

or

ZONE 1or

ZONE 2

SYSTEM CERTIFICATEEXA200 INSTRUMENTSBASEEFA NO Ex 892380

8-1. Cenelec

Ex-classification:EEx ib [ia] IIC T4Zone 0 or 1 Zone 1

SC 200 SVout = 14.4 V max.

Iout = 129 mA max.

C ext = 1 µF maxL ext = 2.3 mH max.

31.5 Vmax4-20 mA

+–

•

•

11

12

14

13

17

15

16IM 12D7B2-E-H

37

8-2. FM

connecting cablessuch as (but not limited to):WU40-LH18 WU40-LH2WU40-LH510 meter Maximum

HAZARDOUS LOCATION

FMRC-Approved Barrier

To be installed in accordance with ANSI/RP 12.6 and NEC requirements

Maximum safe area voltage should not exceed 250 VRMS

NON HAZARDOUS LOCATION

Class I, Division I, Groups ABCDVmax = 31.5 VImax = 93.3 mACi = 5 nFLi = 16.5 uH

ControlDrawing for EXA 200 instruments

1 conductivity sensor with integral SC41-SP34temperature sensor such as (but SC49-FP08not limited to) SC41-SP24

SC41-EP14SC41-EP04

These are all passive sensor to be regarded as "simple apparatus"i.e. devices which do neither store nor generate voltage over 1.2 V,currents over 0.1 A, power over 25 W or energy over 20 mJ

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The EXA SC200 can be used for both con-ductivity and resistivity measurement. Asdelivered the instrument is set for conducti-vity measurement.

9-1. How to change from conductivity toresistivity measurement

- Remove the cover after loosening the 4screws. Now you have access to the Dis-play Board.

- Loosen the 4 screws that hold this boardin place and remove it from the enclosure.

- On the upper back side of the DisplayBoard are 5 blue jumpers. Change thespring jumper as shown in the figure.Make sure that center contact spring issecurely hold to have good contact.

Within 15 seconds after the jumper change,the EXA SC200 will automatically load de-fault data for resistivity measurement.

The SC200 transmitter can be reassemblednow, following the opposite sequence asdescribed above.

9-2.Resistivity measurementAs a resistivity measuring transmitter theEXA SC200 has the same function asdescribed earlier in this manual.

The units mS/cm and µS/cm are replacedby kΩ.cm and MΩ.cm for resistivity meas-urement. If no unit is shown the unit is Ω.cmand can be changed in kΩ.cm by the keyif the “.” is flashing. See range adjustment insection 4-2.

9. CHANGE FROM CONDUCTIVITY TORESISTIVITY MEASUREMENT

fromposition for conductivitymeasurement

toposition for resistivity measurement

9-3.Maintenance of the transmitterCalibration of the resistivity transmitter isdone in the same way as described in sec-tion 5-1.The calibration values can be calculated asfollows:kΩ.cm = 1000 µS/cmΩ.cm = 1000 mS/cm

Example:The 0.001 % NaCI-solution has a conducti-vity value of 21.4 µS/cm. In resistivity modethe value is 1000/21.4 = 46.7 kΩ.cm.

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10. SOFTWARE VERSION 3.0 COM-PARED TO VERSIONS 1* AND 2*.

In 1994 the software of EXA SC200 has un-dergone a major update as result of userfeedback. New features are made accessi-ble by additional Service Codes to avoidprogramming conflicts with users of pre-vious versions.

10-2.Matrix compensationACCESS CODE : 13Display : *MATR

Adjustment:0 Only linear compensation (see access

code 10)1 HCI pure water (0 - 100 °C)/CATION2 Ammonia3 Morpholine in pure water4 Hydrochloric Acid (1-5%)5 Nitric Acid (1-5%)9 User adjustable matrix (see access code 15

NOTE:Access to this routine is only possible whenmanually set temperature compensationfactor (α) is selected in §4-4.

Explanation:The SC200 is equiped with a matrix typealgorithm for accurate temperature compen-sation in various applications. Select therange as close as possible to the actualtemperature/concentration range. TheSC200 will compensate by interpolation andextrapolation. Consequently, there is noneed for a 100 % coverage.If 9 is selected the temperature compensa-tion range for the user adjustable matrix canbe set in access code 15. In access codes16 and 19 the specific conductivity values at5 different temperatures is entered.

The new features are:10-1. Cell constantACCESS-CODE : 05DISPLAY : 1.00xCAdjustments:1. Select multiplying factor2. Adjust the required cell constant

1. Select multiplying factor with keysYES and NO.

2. With keys > and ^ any cell con-stant between 0.01 and 50.0 cm-1

can be selected.

Explanation:1. Multiplying factor

- The multiplying factor is confirmed afterpressing the YES key.- Change multiplying factor to 1.0-10-10-0.01-0.1-1.0 by pressing NO keyand confirm selection with YES key.

2. The value of the cell constant is indicated in the specifications of the cell and/or on itsidentification plate.

Adjust the required value of the cell afterpressing the YES key to confirm the multi-plying factor.Select the digit to adjust with key > (digitflashes).With ^ key the value of the selected digitcan be changed.

Example: Cell constant = 0.00985a. Select multiplying factor 0.01b. Adjust the value to .985

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10-3. Matrix temperature compensationrange

ACCESS CODE : 14Display : *T1 °C

Adjustment: : After selecting 9 in Ac-cess Code 13 the begin-and endscale value oftemperature compensa-tion range of the usersmatrix can be adjustedusing the keys . and ^.

Explanation:In service codes 14 to 18 the SC200 trans-mitter can be fingerprinted to one particularapplication.In access code 13 you have the possibilityto adjust the compensation range.After having access to this routine adjust thebeginscale value of the compensationrange. After entering the beginscale valuethe display indicates T5 °C and the endscalevalue can be adjusted. The temperaturesT2, T3 and T4 are found proportionally.Notes:1. In defining the temperature compensationrange, it is important to select T1 and T5 insuch a way that the 5 reference temperatu-res are user friendly.Example: T1 = 0 and T5 = 80 °C gives ref-

erence temperatures of 0, 20, 40,60 and 80 °C.

2. The minimum span for the range is 50°C(Error code 17 indicates a temperaturerange of less than 50 °C).

10-4. Matrix dataACCESS CODE : 15,16,17,18,19Display : *L1*T1

Adjustment : After adjusting the rangein access code 14 it isnecessary to fill the ma-trix.

Explanation:In these access codes the specific conducti-vity values can be entered for 5 differentconcentrations of the process liquid; eachone in one specific access code (15 to 19).Adjust the conductivity value of the first solu-tion at temperature T1 using keys > and ^.Confirm the adjustment by pressing the ENTkey. The display indication changes to “L1xT2”. Now the conductivity value at tempe-rature T2 can be adjusted. Continue thisprocess unti l “SERV” is displayed andadjustment is finished.Repeat the procedures for solutions 2 to 4in access codes 16 to 19.

NOTES:1. Use the table on page 42 to record your

pro-grammed values. It will make pro-gramming easy for duplicate systems orin case of data loss.

2. Each matrix column has to increase in con-ductivity value:L1 .Tx<L2.Tx<L3.Tx<L4.Tx<L5.Tx

3. Error code E4 occurs when two standardsolutions have identical conductivityvalues at the same temperature within thetemperature range.

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10-5. Selection between ”soft” or ”hard”FAIL Situations

ACCESS CODE : 20Display : *ERR.01

Adjustment:NO Error 01 is skipped; next error is

shownYES 0 = Soft alarm

1 = Hard alarmPressing ENTER confirms the selec-tion

Explanation:As described in chapter 6, the error codesmarked with an asterisk(*) normally will trig-ger a number of actions.If soft alarm action is selected, the FAILmessage flag is flashing. The output func-tions will not go into BURN OUT positionand the contact outputs continue to opera-te.If hard alarm function is selected, the outputgoes into BURN OUT signal if programmedthat way in Access Code 09: and the FAILflag is shown in the display.

10-6. Selection between yes or no E6Fail-message.

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Matrix example actual example actual example actual example actual example action

CODE 14 TEMPERATURE T1 ... T5 O 25 50 75 100

CODE 15 SOLUTION 1 L1 31 53 76 98 119

CODE 16 SOLUTION 2 L2 86 145 207 264 318

CODE 17 SOLUTION 3 L3 146 256 368 473 575

CODE 18 SOLUTION 4 L4 195 359 528 692 847

CODE 19 SOLUTION 5 L5 215 412 647 897 1134

Temp. 0 ppb 4 ppb 10 ppb 20 ppb 100 ppb

Cation 1 0 0,00975 0,152 0,31 0,62 1,23Conductivity 25 0,0559 0,25 0,50 1 2µS/cm 50 0,1752 0,385 0,70 1,35 2,70

75 0,4092 0,62 0,96 1,7 3,3100 0,7681 0,98 1,3 2,1 3,9

Ammonia 2 0 0,00975 0,122 0,23 0,43 0,82Conductivity 25 0,0559 0,25 0,50 1,0 2,0µS/cm 50 0,1752 0,41 0,80 1,62 3,35

75 0,4092 0,65 1,13 2,3 4,8100 0,7681 1 1,52 2,9 5,9

Morpholine 3 0 0,00975 0,149 0,30 0,59 1,15Conductivity 25 0,0559 0,25 0,50 1 2µS/cm 50 0,1752 0,375 0,70 1,38 2,8

75 0,4092 0,60 0,97 1,8 3,55100 0,7681 0,98 1,38 2,35 4,5

1% 2% 3% 4% 5%Hydrochloric 4 0 65 125 179 229 273Acid 15 91 173 248 317 379mS/cm 30 114 217 313 401 4771-5% 45 135 260 370 474 565

60 159 301 430 549 666Nitric Acid 5 0 39,5 76,1 113,4 147,2 179,5mS/cm 20 57,4 108,5 161,4 210 2581-5% 40 81,4 148,1 215 275 330

60 99,9 180,8 260 331 39780 127,8 217 299 374 448

10-7 Matrix examples

IM 12D7B2-E-H

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Instruction Model SC200 Manual 2-wire Conductivity...The EXA SC200 transmitter is a 2-wire...

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