B. manual sensor trim – Yokogawa EJX440A User Manual
Page 29
<3. Operation>
3-19
IM 01C25T01-01E
b. Manual Sensor Trim
Suppose that a standard pressure of 1000 mmH
2
O is
applied and the value of the Pres for Trim in is 994.0.
Correct for this output error of 6 mmH
2
O by adding 6
mmH
2
O to
P LTD.
−4.0+6.0=+2.0
Enter the correction value of 2.
Then press
ENTER (F4).
Suppose that a standard pressure of 3000 mmH
2
O is
applied and the value of the Pres for Trim in is 3015.0.
Firstly, obtain the slope error for the span as follows;
Then correct for this slope error of −10 by adding −10 to
P UTD.
−3.0 + (−10.0) = −13.0
F0332.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
Manual, Lower Pt, and
press
ENTER (F4).
(ENTER)
2
2
EJX:YOKOGAWA
Pres for trim 994.0
Manual, Lower Pt
-4.000000
2
ABORT
DEL
ENTER
(ENTER)
‘2’
Enter the correction value of −13.
Then 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
Manual, Upper Pt, and
press
ENTER (F4).
(ENTER)
4
4
EJX:YOKOGAWA
Pres for trim 3015.0
Manual, Upper Pt
-
3.000000
-
13
ABORT
DEL
ENTER
(ENTER)
‘
−
13’
1. Device setup
2. Diag/Service
3. Calibration
3. Pres sensor trim
2. Pres Trim
Example: For the range of 1000 to 3000 mmH
2
O
P LTD = −4.0 mmH
2
O
P UTD = −3.0 mmH
2
O
Applied Pressure Value – Value of Pres for Trim
Applied Pressure Value
Slope Error =
×(URV–LRV)
3000 − 3015
3000
Ч (3000 − 1000)
=
= −10
Ч3
Ч4
(3) Sensor Trim for Static Pressure
For the EJX differential transmitters, zeroing and
full sensor trim of the static pressure is performed in
the same way as with the primary process variable
(PV). Note that the static pressure sensor trim
should be done only after trimming the PV.
(4) Reset Trim Adjustment to Factory Setting
The
Clear P snsr trim and Clear SP snsr trim
commands can reset the trim adjustment to the
initial calibrated values that were set. The amount
of the adjustment by the external zero-adjustment
screw is returned to the initial setting as well.