Yokogawa EJX440A - Manual (Page 28)

<3. Operation>
3-18
IM 01C25T01-01E
1
1. Device setup
2. Diag/Service
3. Calibration
3. Pres sensor trim
2. Pres Trim
EJX:YOKOGAWA
Select trim mode
1 Off
2 Auto, Lower Pt
3 Auto, Upper Pt
4 Manual, Lower Pt
5 Manual, Upper Pt
ABORT ENTER
F0330.ai
Select the Auto, Lower Pt, and
press ENTER (F4).
(ENTER)
2
EJX:YOKOGAWA
Pres for trim 1383.0
Auto, Lower Pt
0.000000
1350
ABORT DEL ENTER
Enter the value of the actual level
(1350 mmH
2
O), and press
ENTER (F4).
(ENTER)
‘1 3 5 0’
c. Using External Zero-adjustment Screw
This method permits zero adjustment without
the HART communicator. Use a slotted
screwdriver to turn the zero-adjustment screw.
See the hardware manual for details.
Note that the parameter of
Ext SW must be
Enabled to perform this adjustment. See
section 3.5.11 for the setting procedure.
(2) Full Sensor Trim—Auto Trim and Manual
Trim
Full sensor trim is carried out with a series of the
procedure of Auto, Lower Pt and Auto, Upper
Pt. Also, you can manually perform the trimming
procedure in Manual, Lower Pt and Manual,
Upper Pt.
The full sensor trim is a two-point adjustment,
and the lower point adjustment should always be
performed before the upper point adjustment in
order to maintain the pitch between the zero and
100% points within the calibration range.
In the manual method, the reference pressure
should also be applied to the transmitter at both
lower and upper point of trim ends. Without the
reference pressure, P LTD and P UTD may not
represent the correct value of adjustment point for
each.
a. Auto Sensor Trim
Apply a standard pressure of 1000
mmH
2
O to the transmitter. After
obtaining a stable pressure, press
ENTER (F4).
Example: For the range of 1000 to 3000 mmH
2
O
F0331.ai
1
EJX:YOKOGAWA
Select trim mode
1 Off
2 Auto, Lower Pt
3 Auto, Upper Pt
4 Manual, Lower Pt
5 Manual, Upper Pt
ABORT ENTER
Select Auto , Lower Pt, and
press ENTER (F4).
(ENTER)
2
EJX:YOKOGAWA
Pres for trim 994.0
Auto, Lower Pt
1000.000000
1000
ABORT DEL ENTER
(ENTER)
‘1000’
Apply a standard pressure of
3000 mmH
2
O to the transmitter.
After obtaining a stable pressure,
press ENTER (F4).
3
EJX:YOKOGAWA
Select trim mode
1 Off
2 Auto, Lower Pt
3 Auto, Upper Pt
4 Manual, Lower Pt
5 Manual, Upper Pt
ABORT ENTER
Select Auto, Upper Pt, and
press ENTER (F4).
(ENTER)
4
EJX:YOKOGAWA
Pres for trim 3015.0
Auto, Upper Pt
3000.000000
3000
ABORT DEL ENTER
(ENTER)
‘3000’
1. Device setup
2. Diag/Service
3. Calibration
3. Pres sensor trim
2. Pres Trim
Ч2