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3.3 Mounting the Sensor
Mounting the sensor is a very important aspect of the installation, and is
often done incorrectly. In automatic control situations, the sensor should
always be mounted as close as possible to the injection point. This will
cause the sensor to detect the added chemicals immediately, and shut
the addition off until mixing has taken place. For in-line mounting, it is
important that chemicals are injected upstream. Additionally, the line
must be run through a mixing chamber, such as a large drum, to ensure
that the injected chemical has mixed in properly by the time the solution
flows past the sensor. There must always be adequate flow of fresh
sample past the sensor, for accurate monitoring. The diagrams below
show typical mounting arrangements for “dip” mounting and in-line
mounting.
Dip Mounting
In-line Mounting
1. Injection point close to sensor.
1. Injection point upstream from
2. Continuous stirring.
and close to sensor.
2. Mixing container after injection
and before sensor.
3. A flow-through assembly for in-line
mounting is available from TPS.