PU/PI Instruction Manual
9
Display-connector
4
Calibrating the zero point
Please remember that it takes roughly 30 to 60 minutes for the pressure
transmitter to warm up after it is switched on. The output signal may not
remain stable during this period.
It is recommended that the zero point after a long operating time
(approximately 6 months) is checked and if necessary calibrate it again.
The wiring of the current outputmakes it impossible to enter a negative current.
As a result, operators cannot turn the zero-point potentiometer beyond the
0.0 mA mark when calibrating the zero point. Were this not the case, the
negative component, which cannot be displayed, would interfere with the
output signal.
After the pressure transmitter has warmed up, the operator may calibrate the zero
point using the P0 trimmer (see figure 1). The following table may be used to look up
the value to which the analog output must be set when the ports are open; this value
is dependent upon both the measurement range and the output signal.
Output signal
Measurement range
0...10 V
0...20 mA
4...20 mA
± 5 V
± 10 V
0...nominal pressure
0.00 V
0.00 mA
4.00 mA
- 5.00 V - 10.00 V
± nominal pressure
5.00 V
10.00 mA
12.00 mA
0.00 V
0.00 V
asymmetrical measurement
range
the output signal corresponding to the average of both
measurement range limiting values
