APT3500 Smart Pressure Transmitter
Operation Manual M3500-EO1G
57 DUON System Co., Ltd.
Zero Trim and Zero Adjustment are functions
to control offset in the Transmitter
measurement. If a constant error occurs over
the whole region from low pressure to high
pressure as in Figure 5-4, it is possible to
eliminate measurement error by controlling
offset.
In the complete vent mode with no pressure
approval to Transmitter, execution of Zero Trim
can eliminate offset which occurred at the
zero point.
To control the currently measured value to a
certain value without pressure vent, Zero
Adjustment can be executed. In this case,
offset is controlled to move the currently
measured value to desired value. At the time
of Zero Adjustment execution, the currently
approved pressure should be maintained
constantly, and sufficient time should be given for the pressure approved after pressure change
to be stabilized prior to execution. As for Zero offset, set-up value for user and factory initial value
are stored separately, and the factory initial value can always be restored through offset factory
recall function.
As for how to execute Zero Trim and Zero Adjutment making use of button, refer to Chapter 3-7.
As for how to execute Zero Trim and Zero Adjutment making use of HHT, refer to each
corresponding HHT manual or STT30 manual.
A full trim is a two-point sensor
calibration where two end-point
pressures are applied, and all output
is linearized between them. You
should always adjust the low trim
value first to establish the correct
offset. Adjustment of the high trim
value provides a slope correction to
the characterization curve based on
the
low trim value. The factory-
established characterization curve is
not changed by this procedure.
The trim values allow you to optimize
performance over your specified
measuring range at the calibration
temperature.
Simply, Zero Trim & Zero
Adjustment give Offset to the
