Yokogawa EJX210B - Manual (Page 57)

<8. Setting Parameters>
8-22
IM 01C27C01-01EN
(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.
• Procedure to call up the calibration
adjustment parameter (Cal Cmd).
AI1 block: Cal Cmd: CAL_HIGH
Set the upper limit of the measurement range
in CAL_HIGH 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.
(3) Adjustments for Static Pressure
For the EJX differential transmitters, zero point
and span adjustments of static pressure is
performed in the same way as with the primary
process variable (PV).
Adjustment should be performed using the
static pressure (AI2 block) Cal Cmd parameter.
After calibration, confirm the status by using the
static pressure (AI2 block) Cal Status.
• Procedure to call up the calibration
adjustment parameter (Cal Cmd).
AI2 block : Cal Cmd
Perform differential pressure zero/span
adjustment before static pressure zero/span
adjustment.
(4) Reset Adjustment
Reset Adjustment clear the amount of
adjustment. Reset Ajustment can be performed
using CAL_CLEAR of the differential pressure
(AI1 block) Cal Cmd parameter for the input
pressure and using CAL_CLEAR of the static
pressure (AI2 block) Cal Cmd parameter for the
static pressure. After Reset Adjustment, confirm
the status by using Cal Status of the cleared
block. The amount of adjustment made by the
external zero-adjustment screw can be reset to
the initial setting as well.
• Procedure to call up the calibration
adjustment parameter (Cal Cmd).
AI1, AI2 block : Cal Cmd : CAL_CLEAR