14
MultiFix
Description of function
Oxyduo has been developed to constantly measure the oxygen level in the treatment
plant like aeration basins, waterworks, groundwater, lakes etc. The measurement is
shown in text form on the central unit display and presented externally via a 4-‐20 mA
output signal.
Measuring cells
The sensor is fitted with an electro-‐chemical Clark electrode. The sensor body contains
electronics and mechanical parts that must not be subjected to impact. In the event of
damage to the sensor body, water may penetrate and damage the optics/electronics.
There is no way of replacing components; see “Maintenance” for more information.
Configuration
See section describing the MultiFix central unit.
Maintenance
The Oxyduo is designed for minimum maintenance. All metal parts are acid-‐resistant
stainless steel (SS 2343/SS316). The sensor cable is specially made in PUR™ with a
strong shield and extra strands for long life. The sensor and the cable clamps are of the
MatchClamp™ type to guarantee a watertight sensor.
Inspection of the sensor
The sensor head should be cleaned if a deposit has accumulated on the cell. If not, it
could affect the measurements. Use water and a soft sponge. To verify that the
measuring cell is working properly, an air calibration can be performed. See section on
“Calibration”.
Troubleshooting
In the event of malfunctions that cannot be fixed by calibration, contact Cerlic for further
information. Contact Cerlic Controls AB before returning the instrument and fill in the
service form on our website (www.cerlic.se) to simplify processing.
Calibration
The electro-‐chemical measuring cell (Clark electrode) is supplied fitted in the sensor.
Two point calibration (Zero & air) has been performed in factory.
The procedure, described below, can be used to check the functioning of the measuring
cell.
Fig. 13