June 2022 – TD 320 OPERATING MANUAL – TURBIDITY SENSOR 4296
Page 87
Maintenance
The Turbidity Sensor requires very little maintenance.
The sensor should be cleaned at regular intervals depending on the fouling condition at the site.
The Sensor housing can be cleaned using a brush and clean water.
Fouling consisting of calcareous organisms (e.g.
barnacles), can be dissolved by dipping the
sensor/instrument in a weak acid solution (e.g. 7%
Vinegar) over night before cleaning.
If the sensing window is scratched the sensor will still
work but might give bad readings due to spreading of
the transmitted signal.
If severely damaged (so that the sensor gives
unrealistic readings) the sensor need service at the
factory
Annual recalibration is optimal and recommended by
the factory. Although for many applications this may not
be possible. In case where longer calibration intervals
are expected use of a controlled reference can be
adequate to QC the data.
7.1
Function Test
We recommend that you perform a function test of the sensor operating in air to verify the sensor
readings. Refer chapter 7.1.1 for a description of the function test procedure.
Check the turbidity reading in air or in a water sample and check that the temperature sensor
measurements are representative for the ambient temperature where its used.
Figure 7-1: Example of fouling on an RCM 9
