Using The Hart Communicator; Using The Transmitter Zero-Adjustment Screw - YOKOGAWA Dpharp vigilantplant EJA Series User Manual

1.1.1 Using the HART Communicator

(1) Zeroing — Zero trim
NOTE
Zero trim carries out the zero adjustment and
sets the input values at present, equal to 0
mmH O. Use this setting to set LRV = 0 mmH
2
1. Device setup
2. Diag/Service
3. Calibration
3. Sensor trim
1. Zero trim
1
EJA:
WARN-LOOP should be
removed from
automatic control
Press OK (F4).
ABORT OK
2
EJA:
WARN-This will affect
sensor calibration
Press OK (F4).
ABORT OK
3
EJA:
Apply O input to
sensor
A pressure of 0 mmH
ABORT OK
Press OK (F4) after the pressure
has become stable.
(2) Arbitrary Level Adjustment — Lower
Sensor Trim
This zero adjustment applies to tank level measure-
ments, etc. where the actual tank level cannot be set to
zero. For this adjustment, use the actual tank level
obtained with a glass gauge or the like to meet the
DPharp output.
DPharp span: 0 to 2500 mmH
Actual level: 1350 mmH
Transmitter output: 1383 mmH
DPharp
(OK)
(OK)
(OK)
O is applied.
2
O
2
O
2
O
2
2500 mmH O
2
Actual level
1350 mmH O
2
0 mmH O
2
1. Device setup
2. Diag/Service
3. Calibration
3. Sensor trim
2. Lower Sensor Trim
1
EJA:
O.
Apply low pressure
2
2
EJA:
Press OK when
pressure is stable
3
EJA:
ENTER applied
Pressure Value
0.000 mmH2O
0.000
HELP DEL
NOTE
Lower Sensor trim adjusts the input value at
present. See Fine Input Adjustment for detail.
1.1.2 Using the Transmitter Zero-adjust-
ment Screw
F0102.EPS
Turn the zero-adjustment screw on the outside of the
transmitter case using a slotted screwdriver. Turn the
screw to the right to increase the zero point or to the
left to decrease the zero output; the zero adjusts in
increments of 0.01% of the range setting.
Note that the amount of adjustment to the zero point
changes according to the speed at which the screw is
turned. To make fine adjustments, turn the screw
slowly; to make coarse adjustments, turn the screw
quickly.
Note: When a zero point adjustment has been made do not turn of
the transmitter less than 30 seconds after adjustment.
F0103.EPS
1-2
1. ZERO POINT ADJUSTMENT
(OK)
Check the tank level at present, and
ABORT OK
press OK (F4).
(OK)
Press OK (F4).
ABORT OK
'1 3 5 0'
(ENTER)
Enter the value of the actual level
ABORT ENTER
(1350 mmH O), and press ENTER
2
(F4).
F0104.EPS
IM 01C22T01-01E