Commissioning; Polarization; Calibration (Cos22 Only) - Endress+Hauser Oxymax COS22 Kurzanleitung

Commissioning

8 Commissioning
8.1

Polarization

NOTICE
Measurement errors due to environmental conditions
► Urgently protect the sensor from strong sunlight.
► Make sure you comply with the instructions for commissioning and calibration in the Operating
Instructions of the transmitter.
The sensor was tested in the factory for perfect functionality and is supplied ready for operation.
To prepare for calibration, proceed as follows:
1. Remove the sensor protective cap.
2. Place the externally dry sensor in atmospheric air. The air should be saturated with water vapour.
Therefore, install the sensor as close to the water surface as possible. When calibrating the sensor
membrane, make sure the membrane remains dry. Therefore, avoid any direct contact with the
water surface.
3. Connect the sensor to the transmitter and switch on the transmitter.
4. Switch-on the transmitter.
If you connect the sensor to the transmitter, polarization is automatically performed after
switching on the transmitter.
5. Wait for the polarization time to end.
8.2

Calibration (COS22 only)

Calibrate the sensor (air calibration) immediately after the polarization time has elapsed.
The calibration intervals depend heavily on:
• The application and
• The installation position of the sensor.
The following methods help you determine how long the calibration intervals should be:
1. Check the sensor one month after its being put into operation by taking it out of the fluid, drying
it and then measuring the oxygen saturation index at air after 10 minutes.
Decide using the results:
a. If the measured value is not at 100 ± 2 %SAT, you have to calibrate the sensor.
b. Otherwise, double the length of time to the next inspection.
2. Proceed as per Point 1 after two, four and/or eight months. In this way, you can determine the
optimum calibration interval for your sensor.
Be sure to calibrate the sensor at least once a year.
14
Oxymax COS22/COS22D
Endress+Hauser