Calibration; Electrical Calibration; Chemical Calibration - B&C CL 7685 Operator's Manual

B&C Electronics

8 CALIBRATION

8.1 ELECTRICAL CALIBRATION

Should a problem arise with the residual monitor, a sensor simulator can be used to determine if the
electronic unit is working correctly.
Reset the unit to the laboratory calibration (press Keys up+down+enter as described in the parameters
calibration section) and follow the steps:
- Connect to the terminals 18-25 a sensor simulator
(for example OD 105.1 B&C Electronics simulator)
- Simulate the value 0 nA and read the value 0.0 PPM on the display.
- Simulate the value 2000 nA and read the value 1.00 PPM on the display.
Return the unit to the factory if these values will not be displayed.

8.2 CHEMICAL CALIBRATION

Zero cell calibration
The zero calibration is necessary when installing the system and during the initial start up in order to
compensate the eventual dark current of the measuring cell.
Insert the sensor into the flow cell and adjust to the proper flow rate of distilled water.
Allow the reading to stabilize for 10 - 20 minutes prior to setting the zero calibration (it is not essential
that the water be distilled, but it is important that the water is free of Oxidizer).
The zero calibration must be done only after the electric zero calibration that may be effected also
keeping the wet sensor out of the flow cell (in air).
Sensitivity calibration
Always check the zero, the proper flow rate and the stabilization of the readout prior to sensitivity
calibration.
Collect a sample from the effluent or outlet of the flow cell and do a laboratory analysis to determine
the Chlorine (ClO /O
2 3
Follow the sensitivity calibration procedure described in the calibration section.
Clean the Platinum rings of the sensor by means of filter paper or similar prior to starting the
calibration. (see Maintenance section)
Operator's Manual - Rev. C - 05/05
) concentration (DPD method is suggested).
CL 7685
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