Cerabar M, Deltabar M, Deltapilot M / 4...20 mA HART
Commissioning
Hauser
71
6.7
Pressure measurement
6.7.1
Calibration without reference pressure (dry calibration)
Example:
In this example, a device with a 400 mbar (6 psi) sensor is configured for the 0 to +300 mbar (4.5
psi) measuring range, i.e. 0 mbar is assigned to the 4 mA value and 300 mbar (4.5 psi) to the 20
mA value.
Prerequisite:
This is a theoretical calibration, i.e. the pressure values for the lower and upper range are known.
!
Note!
Due to the orientation of the device, there may be pressure shifts in the measured value, i.e. the
measured value is not zero in a pressureless condition. For information on how to perform position
adjustment, see
Description
1
Select the "Pressure" measuring mode via the
"Measuring mode" parameter.
Menu path: Setup
Measuring mode
P01-xxxxxxxx-05-xx-xx-xx-010
Fig. 38:
Calibration without reference pressure
1
See Table, Step 3.
2
See Table, Step 4.
2
Select a pressure unit via the "Press eng. unit" parameter,
here "mbar" for example.
Menu path: Setup
Press. eng. unit
3
Select the "Set LRV" parameter.
Menu path: Setup
Set LRV
Enter the value for the "Set LRV" parameter (here 0
mbar) and confirm. This pressure value is assigned to the
lower current value (4 mA).
4
Select the "Set URV" parameter.
Menu path: Setup
Set URV
Enter the value for the "Set URV" parameter (here
300 mbar (4.5 psi)) and confirm. This pressure value is
assigned to the upper current value (20 mA).
5
Result:
The measuring range is configured for 0 to +300 mbar
(4.5 psi).
20
4
I
[mA]
0
300
p
[mbar]
➀
➁
