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Yokogawa Corporation of America

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EXA DC402 Dual-Channel Conductivity Analyzer

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℉)
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
Conductivity/resistivity Linearity: ±0.5 % FS
Repeatability: ±0.5 % FS
Accuracy: ±0.5 % FS
Temperature 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

Demineralizer Measurements

Ion Exchange is a method for the exchange of ions between two electrolytes or between an electrolyte solution and a complex molecule. In most cases the term is used to denote the processes of purification, separation, and decontamination of aqueous and other ion-containing solutions with solid polymeric or mineralic ion exchangers.

Heat Exchanger Leak Detection

Measurement and control of Heat Exchanger Leakage can help prevent costly maintenance, repair and downtime. The simple, essentially maintenance-free measurement of condensate conductivity will give the operator information necessary (or provide automatic control) to prevent severe damage to the boiler should a breakthrough of the heat exchanger occur.

Pharmaceutical Waters

United States Pharmacopoeia (USP) is the governing body responsible for issuing guidelines for the pharmaceutical industry. Implementing these guidelines is required for companies that bring drugs to the US market. This means that USP is important to all pharmaceutical companies, period.