Maintenance
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Detector unit maintenance procedure
This section describes the maintenance procedures for the residual chlorine detector.
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Checking the sample flow rate
Fluctuations in the sample water flow rate affect the reading of the residual chlorine sensor. A
decrease in the flow rate due to clogging of the piping could cause a decrease in the reading
value. Be sure to check the flow rate of the sample supplied to the measuring cell. The
following describes the procedure to check the flow rate.
For the RA-30, the flow rate can be checked by checking the fluid level within the cell.
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Procedure when using a flow meter
The flow rate of the sample passing through the measuring cell can be checked with a flow
meter.
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Checking the residual chlorine concentration (analyzed value) (cross-check)
As the detector does not use reagents for measurement, the residual chlorine concentration is
more likely to be affected by fluctuations in the water quality. Using a residual chlorine tester
(DPD method) or an equivalent method, check if the concentration excessively deviates from
the appropriate value. It is recommended that it should be checked once a day.
Note
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When using a sampling cock, allow a sample about 500 mL to flow through the cock and clean
the cock. If there is any residual contamination, the reading may be lower than the actual value.
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If a large amount of sample is collected at one time, the amount of sample supplied to the
measuring cell may fall below the required amount and an erroneous value may be indicated. In
order to avoid this, be sure to collect a small amount of sample each time.
Reference
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Refer to “ Calibration ” (page 53).
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Refer to “ Data ” (page 63).
Appropriate
flow rate
Excessive
flow rate
Insufficient
flow rate
Fluid
level
Fluid
level
Fluid
level
