ENDRESS+HAUSER  CCS140-A

Oxidising agents such as chlorine or anorganic chlorine compounds are used for disinfection of water. Their dosing must be carefully controlled to suit the application. Too low a concentration makes the degree of disinfection questionable. Too high a concentration can result in corrosion effects, impairment of taste or skin irritation.

The CCS140 and CCS141 chlorine sensors are applied for measurement of free active chlorine in the following fields:

• Drinking water treatment
• Pool water treatment
• Industrial water treatment

• Measurement in the CCA250 flow assembly is almost independent of flow rate in the range above 30 l/h
• No zero point calibration necessary. This means complicated installation of an active carbon filter, as in open chlorine sensors, is not necessary.
• Measured values are not affected by conductivity fluctuation of the medium.
• The CCS140 sensor is ready for measurement after a polarisation time of approx. 30 ... 60 minutes. The CCS141 sensor requires 45 ... 90 min.
• Easy membrane replacement thanks to ready-made membrane head
• Recalibration intervals approx. 1 ... 4 months under constant operating conditions

The concentration of free chlorine is determined according to the amperometric measuring principle. The hypochlorous acid (HOCl) contained in the medium diffuses through the sensor membrane and is reduced to chloride ions (Cl - ) on the gold cathode. On the silver anode, silver is oxidized to silver chloride. The electron release of the gold cathode and electron acceptance on the silver anode result in a current flow which is proportional to the free chlorine concentration in the medium under constant conditions. The concentration of hypochlorous acid in the medium depends on the pH value. This dependence can be compensated by measuring the pH value in the flow assembly.

The transmitter transforms the current signal into the measuring unit concentration in mg/l.