TriOxmatic
®
690
Measuring / Operation
11
ba25314e05
09/2020
4.3
Function check
The function check is the simplest way of letting you know whether the
sensor needs to be cleaned and calibrated.
Function check in water
vapor-saturated air
Proceed as follows:
Measured values within
the required precision
If the measured value lies within the range of precision required by the
user, no cleaning or recalibrating is necessary.
Example:
The function check can either be performed in water vapor-
saturated air or in air-saturated water.
In the case of air temperatures under 5 °C we recommend
to perform the function check not in air but in air-saturated
water that has a higher temperature.
The function check is carried out in the measuring mode, %
saturation.
1
Take the sensor out of the measuring solution and position it
approx. 2 cm above a water surface, best in a narrow bucket or
similar container with water. When doing so, no drops of liquid
should be on the membrane.
2 cm
2
Wait at least 15 minutes for the temperature to adapt.
3
On the measuring transmitter, select
Saturation
(unit %) and
switch to the measured value display.
4
Read the measured value and determine whether it lies within
the range of precision required by the user.
If there are large temperature differences between the
sample and the air above the surface of the water, a
balancing period of more than 15 minutes may be required.
