Yokogawa Corporation of America

Dual-Channel Conductivity Analyzer

Model Code FLXA21 DC402G
Area Classiffication
  • General Purpose
  • Class I Div II (without the use of IS Barrier)
  • Class I Div I (with the use of IS Barrier)
  • General Purpose
  • Class I Div II
Enclosure Material Plastic (Polycarbonate), Sstainless Steel without Painting, Epoxy Coated SS, Urethane Coated SS Cast Aluminim with chemically resistance coating; polycarbonate cover with polycarbonate flexible windowm
Housing Rating IP66/ NEMA 4A/ CSA 3S IP66/ NEMA 4A/ CSA 3S
Power Supply 2-wire 24VDC, Loop Powered 4-Wire 110-256 VAC, Mains Power
Output Signal Bi-directional HART digital communication, superimposed on mA (4-20mA) signal. Two isolated outputs of 4 to 20 mA DC with common negative.
Flexibility, reliability and low maintenance are among the benefits provided by the EXA DC402G conductivity analyzer. Designed to meet the exacting requirements of measuring dual cell conductivity and resistivity in the modern industrial environment, it contains many features to ensure the best precision whatever the application. Differential, ratio, deviation, % passage or % rejection can be indicated and/or transmitted. This 4-wire converter is housed in a robust IP65 field mountable case. Two mA outputs, four relays, digital communication and a clear LCD make the DC402G a truly comprehensive package. The DC402G features PI control on the auxiliary mA output and the pulse proportional relay outputs, thus avoiding the need for a separate controller.
  • Differential, ratio or calculated outputs
  • Universal conductivity/resistivity, software switchable
  • On-line sensor checking
  • Self-tuning measuring signal
  • Matrix temperature compensation for pure water applications
  • Four fully configurable SPDT contact outputs
  • Two fully configurable mA outputs
  • Built-in PI controller
  • Easy to use EXA control panel
  • USP 23 monitoring
Input specification Two inputs, each 2-electrode measurement with square wave excitation, using cell constants(C) from 0.008 to 50.0 cm-1, with up to 60 meters connection cable
Detection method Frequency, read-pulse position and reference voltage are dynamically optimized.
Input ranges Conductivity:
 Minimum: 1 μS/cm at process temp. (under range 0.000 μSx C).
 Maximum: 25 mS/cm at process temp. (over range 30 mS x C)
Resistivity: 0.00 kΩ/C to 999 MΩ/C at 25℃ (77℉) reference temperature.  Minimum: 40 Ω/C at process temp. (under range 0.001 kΩ x cm).
 Maximum: 1 MΩ/C at process temp. (over range 999 MΩ x cm).
 Pt1000: -20 to 250℃ (0 to 500℉)
 Pt100 and Ni100: -20 to 200℃ (0 to 400℉)
 8k55NTC: -10 to 120℃ (10 to 250℉)
 PB36 NTC: -20 to 120℃ (0 to 250℉)
Conductivity/Resistivity  Linearity: ±0.5 % FS
Repeatability: ±0.5 % FS
Accuracy: ±0.5 % FS
Temperature Accuracy Pt1000Ω, Ni100Ω and PB36 NTC
   Linearity: ±0.3℃
   Repeatability: ±0.3℃
   Accuracy: ±0.3℃
PT100Ω and 8k55Ω
   Linearity: ±0.4℃
   Repeatability: ±0.4℃
   Accuracy: ±0.4℃
Step Response 90 % (< 2 decades) in ≤6 seconds
Output Span Conductivity/Resistivity
 Min. span: 0.010 μS/cm; 0.001 kΩ x cm up to 90 % zero suppression.
 Max. span: 1500 mS/cm; 999 MΩ x cm
Ratio (cell1/cell2): Min. span: 00.0, Max. span: 19.99
Difference (cell1-cell2): Min. span: 0.010 μS/cm, Max. span: 400 mS/cm
% Passage (100 x [cell2/cell1]): Min. span: 00.0, Max. span: 199.9
% Rejection (100 x [(cell1-cell2)/cell1]): Min. span: 0.1, Max. span: 400
% Deviation (100 x [(cell2-cell1)/cell1]): Min. span: 0.1, Max. span: 400
Temperature: Min. span: 25℃ (50℉), Max. span: 250℃ (500℉)
Difference Temperature: Min. span: 25℃ (50℉), Max. span: 250℃ (500℉)
Transmission Signals Two isolated outputs of 0/4 to 20 mA DC with common negative. Maximum load; 600Ω. Auxiliary output can be chosen from conductivity, linearized conductivity/resistivity, temperature, differential temperature calculated value or PI control of conductivity/resistivity. Burn up (22 mA) or Burn down (0/3.5 mA) to signal failure.
Temperature compensation Automatic, for temperature ranges.
Reference temperature: Programmable from 0 to 100℃ (30 to 210℉ (default 25℃ ).
Compensation algorithm According IEC 60746-3 NaCl tables (default).Two independent user programmable temperature coefficients, from 0 to 3.5 % per℃ (deg F) by adjustment or calibration.
Matrix compensation: With conductivity function of concentration and temperature. Choice of 5 preprogrammed matrices and a 25-points user-programmable matrix.
Display Custom liquid crystal display, with a main display of 3 1/2 digits 12.5 mm high.
Contact Outputs Four (4) SPDT relay contacts with LED indicators.
Housing Cast aluminum case with chemically resistant coating, cover with flexible polycarbonate window. Weather resistant to IP65 / NEMA 4X / CSA Type 3S standards. Pipe wall or panel mounting, using optional hardware.
Power Supply Supply voltage rating: 115, 230 V AC, Applicable range: 97.8 to 132.2 /195.5 to 264.5 V AC
Supply frequency rating: 50/60 Hz, Applicable range: 50/60 Hz ± 5%
Power consumption: Maximum 10 VA for steady operation

The model FLXA21® two-wire analyzer is used for continuous on-line measurements in industrial installations. It offers an option for single or dual sensor measurement, making it the most flexible 2-wire analyzer available. The model FLEXA21® modular-designed series analyzer.

  • One analyzer can accept any of 4 types of measurements; pH/ORP, Contacting Conductivity (SC), Inductive Conductivity (ISC) and Dissolved Oxygen (DO)
  • Dual sensor measurement on a 2-wire type analyzer pH/ORP and pH/ORP, SC and SC, and DO and DO
  • Modular design: replaceable sensor modules
  • Redundant system on dual sensor measurement
  • Variety of matierals of construction: SS or Plastice
  • Intuitive easy touch screen operation on 2-wire type analyzer
  • Unique HMI menu structure in 12 languages
  • Quick setup menu for fast and east measurement operation
  • Online Sensor Wellness checking for predictive maintenance
  • NEMA 4X / IP66 Enclosure
Input Specification

Two or four electrode measurement with square wave excitation, using max. 60 m cable and cell constants from 0.005 to 50.0 cm-1

Input Range Conductivity: 0 to 2000 mS/cm at 25ºC (77°F) 
Temperature: -20 to 140ºC (0 to 280°F)  
Conductivity 2 µS x K cm-1 to 200 mS x K cm-1
Accuracy:  ±0.5% F.S. 
 1 µS x K cm-1 to 2 µS x K cm-1     
Accuracy:  ±1% F.S. 
Resitivity 0.005kΩ/ K cm-1 to 0.5MΩ/ K cm-1
Accuracy:  ±0.5% F.S.
0.5MΩ/ x K cm-1 to 1MΩ/ x K cm-1
  Accuracy:  ±1% F.S. 
Temperaure with Pt1000, Pb36, Ni 100
     Accuracy: ± 0.3ºC
with Pt100, NTC 8k55
      Accuracy: ± 0.4ºC
Step Response ≤7 seconds for 90% (for a 2 decade step)
Cable Length Max 60 meters (200 feet). 10 meters (35 feets0 fixed sensor cable + 50 meters (165 feets) WF10 extension cable
Transmission Signal Bi-directional HART digital communicaiton, superimposed on mA (4-20 mA) signal
Temperature Compensation Automatic or manual, for temperature ranges.
Reference temp. programmable from 0-100°C or 30-210°F (default 25°C) 
Calibration Semi-automatic calibration using pre-configured OIML (KCl) standard tables, with automatic stabilit check. Manual adjustment to grab sample.
Display Black and white, 213 x 160 pixels LCD wiht a touch screen
Housing Plastic (polycarbonate), Stainless Steel wihtout painting, Epoxy Coated Stainless Steel, Urethane Coated Stainless Steel
Protection IP66/ NEMA4X/ CSA Type 3S 
Environment Ambient Temperature: -20  to 55°C
Humidity: 10 to 90% RH at 40°C (non-condensig)
 Power Supply Ratings; 17 to 40 V DC 

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