exa conductivity & resistivity analysers · resistivity measurements the semiconductor and...
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Bulletin 12D7A2-E-H
S C 2 0 2 & S C 4 0 2
EXA Conductivity & Resistivity Analysers
Yokogawa’s innovativeonline EXA analysers havelong set the pace inmeasurement and control ofliquid conductivity in manyindustries includingelectricity generation andchemical processing.Precision measurement ofconductivity/resistivitiy isalso required in industrieswhere water quality is criticalsuch as semi-conductors,pharmaceuticals and foodprocessing. The EXA range of high-techanalysers has a proven trackrecord in precisionmeasurement, reliableperformance especiallyunder harsh environmentalconditions, and offer greatflexibility in measurementand output capabilities. Thiscombination of features hasmade EXA analysers anindustry standard. All analysers have built-intwo-way communication forremote control, built-indiagnostics, and pushbutton controls for quickand easy operation,programming andmaintenance. Robustcasings and mountingsensure the analysers are wellprotected for reliableperformance under all typesof environmentalconditions.
Reliability is the key word inanalyser systems: reliabilityin terms of accuratemeasurement and reliabilityin terms of continuousinstrument operation withminimum maintenance.Reliability and lowmaintenance are thus thetwo main criteria for ourcustomers in selectingdifferent types of analysersystems for a processenvironment. But these twoselection criteria do not ruleout ease of use and multi-functions, both of which areimportant to our customersin selecting the bestinstrument for the job.
The cost of defectivemeasurements no matterhow small can beinestimable in a processenvironment, especially ifthe error goes undetected.One of the most commonsources of error, a crackedor fouled sensor, isnotoriously difficult to pickup. Even redundant systemscan give perfectly plausiblereadings despite a smalldefect in the sensor. Thus,reducing and eliminatingthis type of error has beenand continues to be a majorobjective for Yokogawa’sProcess Analyser Division inthe design of the EXA seriesof analyser systems.
The EXA range includes analysers with either a 2-wire or 4-wire transmitter for conductivity and/or resistivitymeasurement as well as a 4-wire dual–cell conductivity analyser ( see Table )
More detailed information can be found in our General Specifications sheet. Please refer to the European web-site (www.yokogawa-europe.com) to contact your nearest representative.
* Specific Conductivity range = Conductivity range * Cell constant (cm-1)
Logbook
The automatic logbook function in PCvieweravailable on all EXA analysers can capture andstore up to 100 user-selectable events, such ascalibration and alarm records. The electroniclogbook provides vital time and cost-savinginformation about predictive maintenance andsystem integrity.
PCviewer software also enables remotereconfiguration of up to 15 analysers on asingle, shielded, 2-wire cable. Furthemore,operators can adjust parameters and high/lowlevels, perform diagnostics, re-range outputs,reset setpoints and manipulate product andtemperature limits. Equally important, remotetroubleshooting eliminates time-consumingdisassembly of the unit in the field.
2-wire 4-wire
SC202 ISC202 SC402 DC402 ISC402
Conductivity range (µS)* 1 – 200,000 1 – 2,000,000 1 – 200,000 1 – 25,000 1 – 2,000,000
Resistivity range (Mohm) 0 - 50 none 0 - 100 0 – 50 none
Temperature Range -20 and 250 °C -20 and 140 °C -20 and 250 °C -20 and 250 °C - 10 and 130°C
(4 to 482 °F) (4 to 284 °F) (4 to 482 °F) (4 to 482 °F) (14 to 266°F)
Power 17 - 40 VDC 17 - 40 VDC 100/115/230 VAC 100/115/230 VAC 100/115/230 VAC
24 VDC 24 VDC 24 VDC
Output 4 to 20 mA 4 to 20 mA 0 (4) to 20 mA 0 (4) to 20 mA 0 (4) to 20 mA
twice twice twice
Input 1 sensor 1 sensor 1 sensor 2 sensors 1 sensor
Contacts none none 4 4 4
Communication HART, FF, Profibus HART, FF, Profibus HART and 2-way HART and 2-way HART and 2-way
2-way with 2-way with with PCviewer with PCviewer
PCviewer (HART) PCviewer (HART)
Hazardous area certification ATEX / CSA / FM ATEX / CSA / FM no no no
A guide to choosing an online conductivity analyser to meet your specific requirements
Remote control
Users in the processindustry want to be able todo more than just examineraw process data. Processengineers want two-waycommunication with theprocess in order to able tomake timely adjustments toimprove process accuracy,reduce waste and improvequality. All EXA analysersoffer dynamic, real-timedata exchange. The vitallink for real-timemonitoring is maintainedvia RS485/Hart protocol orFSK/HART/FF protocol (seeTable 1). Windows 98-based PCviewer softwareenables remote access tocritical data on PC screens inan office, maintenanceworkshop or control room.
Resistivity measurements
The semiconductor and pharmaceutical industrieshave strict requirements for measurement and controlof ultra-pure water flows. That’s why Yokogawa hasincorporated highly sensitive resistivity features andadvanced temperature compensation into several ofthe EXA analysers (EXA SC402, SC202 and DC402;see Table 1).
These analysers are highly sensitive to resistivity inranges up to 18 Megaohm with repeatability andlinearity of 0.002 Megaohm for high-resolutionmonitoring. The system maintains accuracy of 0.005Megohm including temperature compensation usingsimple polynomial equations over the 0-80°C (32–176°F) range.
Designed and built with these critical resistivitymeasurements in mind, EXA SC402 and SC202analysers are available with titanium / SS sensors withadjustable insertion depth. These robust sensors aredesigned for pure-water applications where probescan be exposed to highly corrosive solutions during ionexchange regeneration.
USP guideline
In monitoring waterquality forpharmaceuticalapplications, the USPconductivity section 645edition no. 23 guidelinesets the maximum levelfor uncompensatedconductivity and processtemperature. SC202 andSC402 analysers canmonitor water quality tothis guideline and displayuncompensatedconductivity and processtemperature. The USPcurve is pre-programmedin the SC402 and SC202analysers and is the alarmset point. A warningalarm can be set as apercentage of the USPvalue, and both analysersdisplay a warning codewhen this trigger level isreached.
Self diagnostics
From cooling tower to boiler feed water and condensaterecovery processes, conductivity measurement and control arevital to the efficient operation of an electricity generation plant.Built-in diagnostics in the EXA analysers monitor the cellintegrity and the scaling of sensors for immediate detection of acorrupted signal.
Furthermore, built-in diagnostics can play an important role inplant maintenance and safety by helping ensure secureoperation of water quality processes from the mostconcentrated acids and alkalis to de-ionised feed water, as wellas monitoring condensate leakage. The easy-to-understanddiagnostic signals include upscale and downscale mA outputsfor sophisticated interface and control.
Outputs capabilities
EXA analysers have a widerange of output capabilities,including PI control on boththe contacts (only SC402) andcurrent output. These outputfeatures can be harnessed todrive solenoid valves or feedpumps to create a cost-efficient and reliable controlsystem for many smallapplications. A dedicated FAILcontact output immediatelyalerts users to any error in themeasuring loop.
Temperature compensation
Accurate conductivity measurement is criticalin a reliable control strategy. The precision ofthese vital measurements is increased by theprecision of the EXA SC402 and SC202analysers because of a broad selection oftemperature compensation options.Temperature compensation modes featurecorrection for ultra pure water andconcentrated solutions according to NaCltables, manual compensation, and automaticmatrix temperature compensation (pre-programmed and user-definable) for thespecific applications.
Universal mounting and compatibility
Both the EXA SC402 and SC202 analysershave robust IP65 (NEMA 4X) housingssuitable for field mounting in the harshestindustrial environments and also for panelmounting in a control room.
The flexible but durable polycarbonatefaceplate window allows pushbuttonprogramming and calibration whilemaintaining the weatherproof integrity ofthe enclosure. The EXA SC202 analyser iscertified for hazardous area duty.
On-line mounting adapters usecompression fittings for easy maintenance,a crucial factor in any industry whereprocess downtime is extremely costly.
The SC402 and SC202 analysers arecompatible with a wide range of Yokogawaand other sensors, whether for highconcentration, phase-changing or purewater applications. Specially designedholders for the sensors are available fromYokogawa in a variety of metals andengineering plastics. Flow-through,immersion and retractable assemblies withJIS, EN, DIN or ANSI flanges are compatiblewith most process standards.
Yokogawa quality certification
All Yokogawa analysers are designedto meet rigorous ATEX (CE mark)requirements, and thus comply withthe highest standards in designtesting and manufacture. Theapproval of the Canadian StandardsAssociation and the Factory Mutual(FM) Research Corporation bearsfurther testimony to the Yokogawaquality commitment, especially inelectromagnetic compatibility andnoise immunity.
Model Suffix Option Description
SC202G ........................Conductivity Transmitter
General Purpose version
SC202S ........................Conductivity Transmitter
Intrinsic Safe version
Type -A....................Milli-amp (+HART®) version
-F.....................FOUNDATION® Fieldbus version
-N....................Non-Incendive Milli-amp
(+HART®) version
-B.....................Non-Incendive FOUNDATION®
Fieldbus version
IM -E................English language*
Options /H.......Hood for Sun Protection
/U.......Pipe & Wall mounting hardware
/SCT....Stainless steel tagplate
/Q.......Calibration certificate
/T........Turck Fieldbus connector
Printed in The Netherlands, 02-311 (A)BU12D7A2-E-H Subject to change without notice. Copyright ©
YOKOGAWA EUROPE B.V.Databankweg 203821 AL AMERSFOORTThe NetherlandsTel. +31-33-4641 611Fax +31-33-4641 610E-mail: [email protected]
YOKOGAWA CORPORATION OF AMERICA2 Dart RoadNewnan GA 30265United StatesTel. (1)-770-253-7000Fax (1)-770-251-2088E-mail: [email protected]
YOKOGAWA ELECTRIC ASIA Pte. Ltd.5 Bedok South RoadSingapore 469270SingaporeTel. (65)-241-9933Fax (65)-241-2606E-mail: [email protected]
YOKOGAWA HEADQUARTERS9-32, Nakacho 2-chome,MusashinoshiTokyo 180JapanTel. (81)-422-52-5535Fax (81)-422-55-1202E-mail: [email protected]
Yokogawa has an extensive sales anddistribution network. Please refer to the European web-site(www.yokogawa-europe.com) to contactyour nearest representative.
Unit: mm (inch)
Dimensions SC202
115 (4.5)
92 (3.6)
162 (6.4)
180
(7)
30 (1.2)
Dimensions SC402
144(5.67)
144(
5.67
)
115.
5(4.
55)
24(1
)
16.5(0.65)
Model Suffix Option Descriptioncode code
SC402G .................................... Conductivity/resistivitytransmitter
-E................................. Always ESupply -1 ........................... 115 Volts 50/60 Hzvoltage -2 ........................... 230 Volts 50/60 Hz
-4 ........................... 24 Volts DC-5 ........................... 100 Volts 50/60 Hz
Instruction manual -E .................... English language*Options /U......... Pipe and wall mounting
hardware/PM ...... Panel mounting hardware/Q......... Quality certificate/SCT ..... Stainless steel tag
* For other languages contact local sales office
* For other languages contact local sales office
Specifications SC202
Power supply : up to 40 VDC(Fieldbus Foundation model 9 - 32 volt)
Outputs : 4-20 mAMeasuring range: 0 - 2 S/cmOutput Span : Conductivity : > 0.01µS/cm and < 1999 mS/cm
(max 90% zero suppression)Resistivity : > 0.001 kΩ/cm and < 999 MΩ/cm (max 90% zero suppression)
Temperature : NaCl standard, programmable factor Compensation or 5 x 5 Matrix (pre-programmed or user-
Defined)
Specifications SC402
Power supply : 230, 115 or 100 VAC & 24 VDCOutputs : 2 x 4-20 mA, RS485, 4 x SPDT RelaysMeasuring range: 0 - 2 S/cmOutput Span : Conductivity : > 0.01µS/cm and < 1999 mS/cm
(max 90% zero suppression)Resistivity : > 0.001 kΩ/cm and < 999 MΩ/cm (max 90% zero suppression)
Temperature : NaCl standard, programmable factor Compensation or 5 x 5 Matrix (pre-programmed or user-
Defined)