Type 8232

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5.

Product installation

5.1. Installation notes

Measuring chamber Description

The requirements for maintaining and monitoring a constant flow rate of the analysed water, necessitate the

use of an appropriate measuring chamber. Thus the sensor Type 8232 has to be installed in the analytical

measuring chamber Type 8200. Otherwise the liability for a proper function of the sensor will be declined.

See data sheet Type 8200  for more information.

This analytical measurement chamber has to be installed so that the inserted chlorine sensor is in an upright

position, and so that the incoming flow rate comes from the bottom up to the membrane.

Gas bubbles at the membrane leads to incorrect measuring signals.

For continuous flow monitoring, an inductive flow switch is available optionally, to be mounted in the analyti-

cal measurement chamber Type 8200.

Do not install the sensor in the main pipe. Measure only in bypass with use of the analytical measur-

ing chamber Type 8200.

6.

Product operation

6.1. Measuring principle

Depending on the variant, the 8232 Sensor measures either the free chlorine or the total chlorine content. Total chlorine is the sum

of free chlorine (disinfectant chlorine) and bound chlorine (Concentration of chlorine combined with organic and inorganic nitrogen

compounds present in the water).

The chlorine sensor is a two or three-electrode measuring system (depends on variant) covered with a membrane. The membrane

cap filled with a special electrolyte, protects the working and reference electrodes from direct contact with the measuring water. With

this measuring method, ionic substances in the water are held back by the membrane, whereas the substance to be determined

(disinfectant or chlorine) can pass through the membrane without restriction. The diffusion of the substance through the membrane

ensures that the concentrations on both sides of the membrane are equal and causes an electrical signal on the working electrode.

The 2-electrode measuring system consists of a working electrode and a reference electrode, between which a certain voltage (po-

larization voltage) is applied. The 3-electrode measuring system consists of a working electrode, a reference electrode and a counter

electrode. The measuring signal at the working electrode is proportional to the concentration of the disinfectant or to the chlorine

concentration and is amplified by the electronics of the sensor. The measuring signal is independent from the temperature of the

measuring water due to an integrated temperature compensation.

The calibration must be done on a transmitter/controller with a reference value. The transmitter Type 8619 multiCELL is suited and

recommended, but any other suited transmitter can be also used.

See data sheet Type 8619  for more information.

7.

Product design and assembly

7.1. Product features

Note:

The following table gives an overview of the features for sensor selection.

Feature details

Free chlorine sensor

Total chlorine sensor

“Trace” (zero-chlorine) with 3 electrodes

with 2 electrodes

with 3  electrodes

Works in water without chlorine

for up to 4 weeks

Yes

No

No

No

Galvanically isolated

Yes

No

No

No

Greatly reduced pH dependency

Yes1.)

Yes

No

Yes

Surfactants are partially tolerated Yes

Yes

No

Yes

Temperature compensation

Yes

Yes

Yes

Yes

Zero-Point stability

Yes

Yes

Yes

Yes

Membrane covered

Yes

Yes

Yes

Yes

Two-wire device

No

Yes

Yes

Yes

1.) Chlorine sensor “Trace” has a higher pH dependency compared to the chlorine sensor with 3 electrodes.