Yokogawa EJX930A - Manual (Page 22)

<3. Parameter Setting>
3-12
IM 01C25R05-01EN
<3> Enter the correction value of “2” to the Pres
LTD (Manual, Lower Pt).
<4> Call up the Pres UTD (Manual, Upper Pt).
<5> Suppose that a standard pressure of 3000
mmH
2
O is applied and the value of the Pres for
trim is 3015.0. Firstly, obtain the slope error for
the span as follows;
Slope Error =
Applied Pressure Value−Value of Pres for Trim
× (URV−LRV)
Applied Pressure Value
=
3000−3015
× (3000−1000) = −10
3000
Then correct for this slope error of −10 by adding
−10 to Pres UTD (Manual, Upper Pt).
−3.0+(−10.0)=−13.0
<6> Enter the correction value of “−13” to the Pres
UTD (Manual, Upper Pt).
(3) Sensor Trim for Static Pressure or External
Temperature
For the EJX multivariable transmitter, full sensor
trim of the static pressure or external temperature is
performed in the same way as with the differential
pressure.
• Procedure to call up the display for static
pressure
[Root Menu] → Diag/Service → Calibration → SP
sensor trim → SP trim →
→ Auto, Lower Pt
Auto trim for 0% point
→ Auto, Upper Pt Auto trim for 100% point
→ Manual, Lower Pt Manual trim for 0% point
→ Manual, Upper Pt Manual trim for 100% point
• Procedure to call up the display for external
temperature
[Root Menu] → Diag/Service → Calibration → ET
Sensor trim → ET trim →
→ Auto, Lower Pt
Auto trim for 0% point
→ Auto, Upper Pt Auto trim for 100% point
→ Manual, Lower Pt Manual trim for 0% point
→ Manual, Upper Pt Manual trim for 100% point
(4) Reset Trim Adjistment to Factory Setting
The
Clear P trim, Clear SP trim and Clear ET trim
commands can reset the trim adjustment to the
initial calibrated values that were set. The amount of
the adjustment performed with the external zero-
adjustment screw is returned to the initial setting as
well.
• Procedure to call up the display for differential
pressure
[Root Menu] → Diag/Service → Calibration → Pres
Sensor trim → Clear P trim → Execute
• Procedure to call up the display for static
pressure
[Root Menu] → Diag/Service → Calibration → SP
Sensor trim → Clear SP trim → Execute
• Procedure to call up the display for external
temperature
[Root Menu] → Diag/Service → Calibration → ET
Sensor trim → Clear ET trim → Execute
(5) Calibration flag
When the
Calibration Flag parameter is set,
the corresponding status bit in Status Bits and
Status Bytes parameter in Address Map (Basic
Information) will turn ON. The Calibration Flag
parameter is used only for informational use and
does not affect the internal operation of the EJX
Multivariable transmitter. Regarding the Calibration
Flag parameter, refer to 4.1.1.
• Procedure to call up the display
[Root Menu] →Diag/Service → Calibration
→Calibration Flag
→ Calibration Flag
Flag the transmitter is in a
calibration State.
3.4.5 External Switch Mode
Follow the procedure below to enable or inhibit zero
point adjustment by means of the zero-adjustment
screw on the transmitter.
This is set to “Disable” when the instrument is
shipped.
To change the mode, follow the procedure below.
• Procedure to call up the display
[Root Menu] → Detailed setup → Device information
→ Field device info → Ext SW
Enabled
Enable the external zero point
adjustment
Disabled Disable the external zero point
adjustment