Function
Oxymax H COS21D
20
Hauser
• Reference:
– Offset
– Slope
!
Note!
The following section
only
describes the calibration in air (saturated with water vapor) as the
easiest method of calibration and therefore the recommended method.
However, this type of calibration is only possible if the air temperature is
≥
–5 °C (23 °F).
5.3.2
Calibration in air
1.
Remove the sensor from the medium.
2.
Clean the outside of the sensor with a damp cloth.
Then dry the sensor membrane e.g. by using a tissue.
3.
If the sensor is removed from a closed pressure system with a process pressure greater than
atmospheric pressure:
– Open the membrane cap to equilibrate the pressure and clean the cap if necessary.
– Replace the electrolyte filling and close the membrane cap again.
– Wait for the polarization time to end.
4.
Then wait while the sensor adjusts to the temperature of the ambient air. This takes about
20 minutes. Check that the sensor is not in direct sunlight during this time.
5.
If the measured value display on the transmitter is stable, carry out the calibration in
accordance with the Operating Instructions of the transmitter.
6.
Place the sensor in the medium again.
!
Note!
Make sure you comply with the instructions for calibration in the Operating Instructions of the
transmitter.
5.3.3
Calculation example for the calibration value
As a check, you can calculate the expected calibration value (transmitter display) as shown in
the following example (salinity is 0).
1.
Determine:
– The ambient temperature for the sensor (air temperature for "air" calibration
method,water temperature for "air-saturated water" calibration type)
– the altitude above sea level
– the current air pressure (=rel. air pressure to sea level) at the time of calibration. (If
undeterminable, use 1013 hPa (407 inH
2
O) for an approximate calculation.)
2.
Define:
– the saturation value
S
acc. to the first table
– the factor
K
acc. to the second table
