Endress+Hauser CCS120D, Operating Instructions Manual

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CCS120D Commissioning
Hauser 25
Requirements
The sensor reading is stable (no drifts or unsteady values for at least 5 minutes). This is
normally guaranteed once the following preconditions have been met:
• The polarization period has elapsed.
• The flow is constant and within the correct range.
• The sensor and the medium are at the same temperature.
• The pH value is within the permitted range.
Zero point adjustment
A zero point adjustment is not required due to the zero point stability of the membrane-
covered sensor.
Slope calibration
Always perform a slope calibration in the following cases:
• After replacing the membrane cap
• After replacing electrolyte
The slope of the sensor is strongly influenced by the application conditions. The interval
for the slope calibration must be adjusted accordingly.
Repeat the slope calibration at regular intervals.
Recommended calibration intervals →  28
1. Ensure that the pH value and temperature of the medium are constant.
2. Take a representative sample for the DPD measurement. This must be done in close
proximity to the sensor. Use the sampling tap if available.
3. Determine the chlorine content using the DPD method.
4. Enter the measured value into the transmitter (see Operating Instructions for
transmitter).
5. To ensure greater accuracy, check the calibration several hours or 24 hours later using
the DPD method.