Zero Point/Limit Point; The Difference Between Setting And Adjusting - Siemens SITRANS P300 Operating Instructions Manual

See also
Releasing key or function lock (Page 6-30)
6.5.4

Zero point/limit point

6.5.4.1

The difference between setting and adjusting

Introduction
With the "Pressure" measurement type, you set or adjust the zero point and limit point with
the keys. Modes 2 and 3 are used for this. Rising and falling characteristic curves can be
realized with appropriate use of the keys. If the transmitter is not using the "Pressure"
measurement type, this mode is skipped in local operation.
Difference
The difference between setting and adjusting lies in the calculation.
Setting with reference pressure
Requirement
Two reference pressures p
the process or generated by a pressure sensor.
With setting, a desired zero point or limit point is allocated to the standard current values (4
mA or 20 mA) After setting, the span specified on the nameplate may no longer correspond
with the adjustment.
Depending on the model and measuring range, a maximum downscaling of 1:100 can be
achieved (span ratio = r, turn down).
Note
Setting the zero point does not change the span. Setting the limit point does not change the
zero point.
The zero point should therefore be set first, then the limit point.
SITRANS P300 with HART communication
Operating Instructions, 06/2005, A5E00359579-02
Note
If more than 2 minutes has passed since the last key was pressed, the setting is
automatically saved and the device automatically returns to the measured value display.
and p are available. The reference pressures are initialized by
r1 r2
Operation
6.5 Local operation
6-13