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Chlorine Sensor GCM

The total chlorine sensor GCM serves to determine the total chlorine concentration of potable water, pool water or water of comparable quality. The sensor is mounted to the sampling station DCM 01. The TOPAX NT serves as measuring and control unit.

Only by using the sampling station DCM 01 the desired inflow parameters are achieved which are necessary for a safe operation of the sensor. The sampling station DCM 01 must be operated in a pressureless condition. For monitoring the flow, a flowmeter is provided which opens a contact when no flow is present. This contact sets the control of the connected TOPAX NT to 0 % thus avoiding undefined metering. The total chlorine sensor has to be serviced and checked for impurities, plant contamination and air bubbles regularly. Impurities can be removed by means of a water jet.

Materials of Construction

The chlorine measuring cell consists of an electrode shaft and a diaphragm cap. The diaphragm cap is filled with an electrolyte and serves as a measuring chamber into which the measuring electrodes are submerged.

The measuring chamber is isolated from the sample medium by means of a microporous diaphragm. The chlorine sensor is a diaphragm-covered amperiometric two-electrode probe. The working electrode is a platinum cathode and the counter electrode is a silver anode. The sensor signal is almost independent of the pH-value in the operational range of the sensor.

The amplifier electronic unit converts the primary sensor current into a constant current of 4...20 mA. The connection to the subsequent measuring device is accomplished by means of a two-core cable , which means that the voltage supply of the amplifier electronic unit is achieved by means of the connected measuring and control device TOPAX NT. The measuring value is temperature compensated by means of the amplifier electronic unit.

Technical Data

Measured variable - total chlorine (free and combined chlorine)
Measuring range - 0.02 to 2.00 mg/l
Resolution - 0.02 mg/l
pH range - 5.5 to 9.5
Temperature range - 5 to 45 °C (temperature compensated)
Storage temperature - frostfree between 5 and 50°C
Inflow - min. - 20 l/h
Inflow - max - 100 l/h
Inflow - recommended - 30 l/h (sampling station DCM01)
Cross sensitivity - bromine, iodine, ClO2 lead to measuring errors
Operation life - typically 1 year depending on water quality
Supply voltage - 16 to 24 VDC; min 35 mA at 16 VDC
Output signal - 4 to 20 mA
Protection class - IP 65