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1 INTRODUCTION
1.1
General Description
The De Nora Water Technologies chlorine gas leak detector, CHLORALERT™ T17CA4000, continually monitors air
samples for the presence of chlorine. It is usually installed in chlorine usage and storage areas to protect personnel
and equipment.
A small internal air blower continually draws a sample of air into the Chloralert. The flowmeter and valve enable a
fixed amount of air to be passed over the surface of the special electrolyte, where the chemical reaction takes place
in presence of chlorine. Two platinum electrodes, half immersed in the electrolyte, pick up the electrochemical
current thus generated which is measured by the electronic circuit and used to trigger an alarm system.
The trip point may be factory set to 1 or 3 ppm chlorine in air by volume. The power on/alarm lamp commences
flashing in the alarm condition.
In the Model T17CA4100, a relay is also energized to enable external alarms, extractor fans etc. to be activated. The
alarm condition is generated, in addition to the presence of chlorine in air, also by power failures, when the power is
returned to the system.
In the Model T17CA4200, a relay is also de-energized to enable external alarms, extractor fans etc. to be activated.
The electrical circuits are designed such that power supply failure causes the alarm relay to go into the alarm state.
A flow sensor detects when there is no sample flow and causes the alarm relay to go into the alarm state. The
sample fan is stopped when the alarm condition is actuated, to prevent saturation of electrolyte with chlorine and
contaminated air to be discharged in safe area through the Chloralert™ itself.
The unit has an integral electrical test facility.
The alarm needs operator's acknowledgment to be reset.
Figure 1 - CHLORALERT Internal View