EXA Conductivity & Resistivity Analysers S C202 & S C402 Bulletin 12D7A2-E-H
Yokogawa s innovative online EXA analysers have long set the pace in measurement and control of liquid conductivity in many industries including electricity generation and chemical processing. Precision measurement of conductivity/resistivitiy is also required in industries where water quality is critical such as semi-conductors, pharmaceuticals and food processing. The EXA range of high-tech analysers has a proven track record in precision measurement, reliable performance especially under harsh environmental conditions, and offer great flexibility in measurement and output capabilities. This combination of features has made EXA analysers an industry standard. All analysers have built-in two-way communication for remote control, built-in diagnostics, and push button controls for quick and easy operation, programming and maintenance. Robust casings and mountings ensure the analysers are well protected for reliable performance under all types of environmental conditions.
Reliability is the key word in analyser systems: reliability in terms of accurate measurement and reliability in terms of continuous instrument operation with minimum maintenance. Reliability and low maintenance are thus the two main criteria for our customers in selecting different types of analyser systems for a process environment. But these two selection criteria do not rule out ease of use and multifunctions, both of which are important to our customers in selecting the best instrument for the job. The cost of defective measurements no matter how small can be inestimable in a process environment, especially if the error goes undetected. One of the most common sources of error, a cracked or fouled sensor, is notoriously difficult to pick up. Even redundant systems can give perfectly plausible readings despite a small defect in the sensor. Thus, reducing and eliminating this type of error has been and continues to be a major objective for Yokogawa s Process Analyser Division in the design of the EXA series of analyser systems.
The EXA range includes analysers with either a 2-wire or 4-wire transmitter for conductivity and/or resistivity measurement as well as a 4-wire dual cell conductivity analyser ( see Table ) A guide to choosing an online conductivity analyser to meet your specific requirements 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 * Specific Conductivity range = Conductivity range * Cell constant (cm -1 ) 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. Remote control Users in the process industry want to be able to do more than just examine raw process data. Process engineers want two-way communication with the process in order to able to make timely adjustments to improve process accuracy, reduce waste and improve quality. All EXA analysers offer dynamic, real-time data exchange. The vital link for real-time monitoring is maintained via RS485/Hart protocol or FSK/HART/FF protocol (see Table 1). Windows 98- based PCviewer software enables remote access to critical data on PC screens in an office, maintenance workshop or control room. Logbook The automatic logbook function in PCviewer available on all EXA analysers can capture and store up to 100 user-selectable events, such as calibration and alarm records. The electronic logbook provides vital time and cost-saving information about predictive maintenance and system integrity. PCviewer software also enables remote reconfiguration of up to 15 analysers on a single, shielded, 2-wire cable. Furthemore, operators can adjust parameters and high/low levels, perform diagnostics, re-range outputs, reset setpoints and manipulate product and temperature limits. Equally important, remote troubleshooting eliminates time-consuming disassembly of the unit in the field.
Resistivity measurements The semiconductor and pharmaceutical industries have strict requirements for measurement and control of ultra-pure water flows. That s why Yokogawa has incorporated highly sensitive resistivity features and advanced temperature compensation into several of the EXA analysers (EXA SC402, SC202 and DC402; see Table 1). These analysers are highly sensitive to resistivity in ranges up to 18 Megaohm with repeatability and linearity of 0.002 Megaohm for high-resolution monitoring. The system maintains accuracy of 0.005 Megohm including temperature compensation using simple polynomial equations over the 0-80 C (32 176 F) range. USP guideline Designed and built with these critical resistivity measurements in mind, EXA SC402 and SC202 analysers are available with titanium / SS sensors with adjustable insertion depth. These robust sensors are designed for pure-water applications where probes can be exposed to highly corrosive solutions during ion exchange regeneration. In monitoring water quality for pharmaceutical applications, the USP conductivity section 645 edition no. 23 guideline sets the maximum level for uncompensated conductivity and process temperature. SC202 and SC402 analysers can monitor water quality to this guideline and display uncompensated conductivity and process temperature. The USP curve is pre-programmed in the SC402 and SC202 analysers and is the alarm set point. A warning alarm can be set as a percentage of the USP value, and both analysers display a warning code when this trigger level is reached.
Self diagnostics From cooling tower to boiler feed water and condensate recovery processes, conductivity measurement and control are vital to the efficient operation of an electricity generation plant. Built-in diagnostics in the EXA analysers monitor the cell integrity and the scaling of sensors for immediate detection of a corrupted signal. Furthermore, built-in diagnostics can play an important role in plant maintenance and safety by helping ensure secure operation of water quality processes from the most concentrated acids and alkalis to de-ionised feed water, as well as monitoring condensate leakage. The easy-to-understand diagnostic signals include upscale and downscale ma outputs for sophisticated interface and control. Temperature compensation Outputs capabilities EXA analysers have a wide range of output capabilities, including PI control on both the contacts (only SC402) and current output. These output features can be harnessed to drive solenoid valves or feed pumps to create a costefficient and reliable control system for many small applications. A dedicated FAIL contact output immediately alerts users to any error in the measuring loop. Accurate conductivity measurement is critical in a reliable control strategy. The precision of these vital measurements is increased by the precision of the EXA SC402 and SC202 analysers because of a broad selection of temperature compensation options. Temperature compensation modes feature correction for ultra pure water and concentrated solutions according to NaCl tables, manual compensation, and automatic matrix temperature compensation (preprogrammed and user-definable) for the specific applications.
Universal mounting and compatibility Both the EXA SC402 and SC202 analysers have robust IP65 (NEMA 4X) housings suitable for field mounting in the harshest industrial environments and also for panel mounting in a control room. The flexible but durable polycarbonate faceplate window allows pushbutton programming and calibration while maintaining the weatherproof integrity of the enclosure. The EXA SC202 analyser is certified for hazardous area duty. On-line mounting adapters use compression fittings for easy maintenance, a crucial factor in any industry where process downtime is extremely costly. The SC402 and SC202 analysers are compatible with a wide range of Yokogawa and other sensors, whether for high concentration, phase-changing or pure water applications. Specially designed holders for the sensors are available from Yokogawa in a variety of metals and engineering plastics. Flow-through, immersion and retractable assemblies with JIS, EN, DIN or ANSI flanges are compatible with most process standards. Yokogawa quality certification All Yokogawa analysers are designed to meet rigorous ATEX (CE mark) requirements, and thus comply with the highest standards in design testing and manufacture. The approval of the Canadian Standards Association and the Factory Mutual (FM) Research Corporation bears further testimony to the Yokogawa quality commitment, especially in electromagnetic compatibility and noise immunity.
Dimensions SC202 162 (6.4) Unit: mm (inch) Dimensions SC402 144(5.67) 16.5 (0.65) 180 (7) 30 (1.2) 144(5.67) 115.5(4.55) 92 (3.6) 115 (4.5) 24(1) Specifications SC202 Power supply : up to 40 VDC (Fieldbus Foundation model 9-32 volt) Outputs : 4-20 ma Measuring range: 0-2 S/cm Output 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 VDC Outputs : 2 x 4-20 ma, RS485, 4 x SPDT Relays Measuring range: 0-2 S/cm Output 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) 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 * For other languages contact local sales office Model Suffix Option Description code code SC402G... Conductivity/resistivity transmitter -E... Always E Supply -1... 115 Volts 50/60 Hz voltage -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 YOKOGAWA HEADQUARTERS 9-32, Nakacho 2-chome, Musashinoshi Tokyo 180 Japan Tel. (81)-422-52-5535 Fax (81)-422-55-1202 E-mail: webinfo@mls.yokogawa.co.jp www.yokogawa.com YOKOGAWA CORPORATION OF AMERICA 2 Dart Road Newnan GA 30265 United States Tel. (1)-770-253-7000 Fax (1)-770-251-2088 E-mail: info@yca.com www.yca.com Yokogawa has an extensive sales and distribution network. Please refer to the European web-site (www.yokogawa-europe.com) to contact your nearest representative. YOKOGAWA EUROPE B.V. Databankweg 20 3821 AL AMERSFOORT The Netherlands Tel. +31-33-4641 611 Fax +31-33-4641 610 E-mail: info@nl.yokogawa.com www.yokogawa-europe.com YOKOGAWA ELECTRIC ASIA Pte. Ltd. 5 Bedok South Road Singapore 469270 Singapore Tel. (65)-241-9933 Fax (65)-241-2606 E-mail: webinfo@yas.com.sg www.yokogawa.com.sg BU12D7A2-E-H Subject to change without notice. Copyright Printed in The Netherlands, 02-311 (A)