<8. Setting Parameters>
8-14
IM 01C27C01-01EN
c. Using External Zero-adjustment Screw
External Zero-adjustment parameter (External
Zero Trim) can set permission or prohibition to
adjustment by External Zero-adjustment Screw.
Set “Trim on” to use the External Zero-
adjustment Screw. (“Trim on” at shipment)
Use a slotted screwdriver to turn the zero
adjustment screw. Turn the screw clockwise
to increase the output or counterclockwise to
decrease the output. The zero point adjustment
can be made with a resolution of 0.01% of the
setting range.
The degree of zero adjustments varies with
the screw turning speed; turn the screw slowly
to make a fine adjustment, quickly to make a
rough adjustment.
Zero-adjustment Screw
F0807.ai
Figure 8.4
Zero-adjustment Screw
(2) Span Adjustment
Span Adjustment is function to change the
input and output characteristic that assumed
the bottom value (zero point) of measurement
range as a standard.
Therefore, perform span adjustment
(adjustment of the upper limit value) after zero
adjustment (adjustment of bottom limit value).
After adding the pressure at point of adjustment
and setting pressure value as parameter, the
transmitter calculates quantity of adjustment
and performs adjustment automatically.
• Procedure to call up the lower limit value
parameter (Calibration Lowest Point).
AI1 block : Calibration Lowest Point
Set the lower limit adjustment value on the
differential pressure (AI1 block) Calibration
Lowest Point parameter screen. Apply a
reference pressure corresponding to the
lower limit of the measurement range to the
differential pressure/pressure transmitter
and set the reference pressure when it has
stabilized.
• Procedure to call up the calibration
adjustment parameter (Cal Cmd).
AI1 block : Cal Cmd : CAL_LOW
Set the lower limit of the measurement range
in CAL_LOW of the differential pressure
(AI1 block) Cal Cmd parameter.
• Procedure to call up the calibration status
parameter (Cal Status).
AI1 block : Cal Status
Confirm the value of CAL_SUCCESS (1)
using the Cal Status parameter.
• Procedure to call up the upper limit
adjustment parameter (Calibration Highest
Point).
AI1 block : Calibration Highest PointI
Set the upper limit adjustment value for the
differential pressure (AI1 block) Calibration
Highest PointI parameter. Apply a reference
pressure corresponding to the upper limit of
the measurement range to the differential
pressure/pressure transmitter and set the
reference pressure when it has stabilized.
