Vaisala FD12P - Manual (Page 124)

User's Guide _______________________________________________________________________
124 _____________________________________________________ M210296en-A
Calibrating the DTS14B Temperature Sensor
Calibration of the DTS14 Temperature Sensor is recommended to be
carried out once a year. For the sensor accuracy, only 0 °C
temperature is important as this temperature is used to identify
freezing rain. The TCAL command is used for the calibration of the
surface temperature (TS) measurement.
For the calibration, prepare an ice bath into a thermos flask and
remove the DTS14 sensor from the mast.
Remove the holder from the mast in the following way:
1. Open the fixing screw fully (part 3).
2. Push the screw head to the hole with your finger.
3. Slide the holder downwards as long as it goes.
4. Pull the holder and sensor away from mast hole.
5. Open the screw holding the DTS14 and pull the sensor out of
the holder.
6. Hang a thermos flask with a S-shaped hook to the hole for
example.
7. Put the DTS14B temperature sensor into the ice bath.
8. To see the current scaling factors and current TS, give the
TCAL
↵ command. Then give the
FREQ
↵ command.
Wait for five minutes to allow the measurement stabilize. If the
TS is 0.0°C
±0.1°C, adjustment is not necessary. Otherwise,
continue with the calibration procedure.
9. Terminate the command by pressing the ESC key.
10. Give the TCAL TS 0.0 command. The command makes the zero
calibration, if temperature sensor DTS14 is at 0°C temperature.
Give the FREQ command and wait again to see that the new TS
value is correct.
11. Terminate the command by pressing the ESC key.
12. After calibration, fix the DTS14 to the sensor holder and mount
the holder to the mast.