Sensor Trim - YOKOGAWA Dpharp vigilantplant EJA Series User Manual

CAUTION
1. Test output is held for approximately 10
minutes, and then released automatically
after the time has elapsed. Even if the HART
Communicator power supply is turned off or
the communication cable is disconnected
during test output, it is held for approximately
10 minutes.
2. Press the (OK) key to release test output
immediately.

(13) Sensor Trim

Each DPharp EJA Series Transmitter is factory
characterized. Factory characterization is the process of
comparing a known pressure input with the output of
each transmitter sensor module over the entire pressure
and temperature operating range. During the character-
ization process, this comparison information is stored
in the transmitter EEPROM. In operation, the transmit-
ter uses this factory-stored curve to produce a process
variable output (PV), in engineering units, dependent
on the pressure input. The sensor trim calibration
procedure allows you to make corrections to the
calculated process variable.
There are two ways to trim the sensor: full sensor trim
and zero trim. A full sensor trim is a two point process,
in which two accurate end-point pressures are applied
(equal to or greater than the range values), and all
output is linearized between them. A zero trim is a
one-point adjustment typically used to compensate for
mounting position effects or zero shifts caused by static
pressure. (See section 1.1.1)
Example 1: For the range of 1000 to 3000 mmH
1. Device setup
2. Diag/Service
3. Calibration
3. Sensor Trim
1
EJA:
Sensor trim
1 Zero trim
2 Pres
3 Lower sensor trim
Select the Lower Sensor trim.
4 Upper sensor trim
5 Sensor trim points
HELP SET HOME OK
2
EJA:
Apply low pressure
Apply a standard pressure of 1000
mmH
DEL SET ABORT OK
obtaining a stable pressure, press
OK (F4).
O
2
(OK)
O to the transmitter. After
2
F02281.EPS
2. HART COMMUNICATOR OPERATION
3
EJA:
Press OK when
pressure is stable
HELP DEL ABORT OK
4
EJA:
Enter applied
pressure value
0.00 mmH2O
0.00
HELP DEL ABORT ENTER
SPAN adjustment shall be carried out with Upper
Sensor trim. After selecting Upper Sensor trim,
apply a pressure of 3000 mmH
100% of the measurement range). Then, proceed the
same as for the operations for Lower Sensor trim.
1
EJA:
Sensor trim
1 Zero Trim
2 Pres
3 Lower sensor trim
4 Upper sensor trim
5 Sensor trim points
HELP SET HOME OK
2
EJA:
Apply hi pressure
DEL SET ABORT OK
3
EJA:
Press OK when
pressure is stable
HELP DEL ABORT OK
4
EJA:
Enter applied
Pressure value
0.00 mmH2O
0.00
HELP DEL ABORT ENTER
2-13
(OK)
Press OK (F4).
'1 0 0 0'
(ENTER)
Enter 1000, and press ENTER (F4).
Remove pressure appears for a
while.
Fine input adjustment (0%) is
complete.
O (corresponding to
2
Select the Upper Sensor trim item.
(OK)
Apply a standard pressure of 300
mmH O to the transmitter. After
2
obtaining a stable pressure, press
OK (F4).
(OK)
Press OK (F4).
'3 0 0 0'
(OK)
Enter 3000, and press ENTER (F4).
Remove pressure appears for a
while.
Fine input adjustment (100%) is
complete.
IM 01C22T01-01E
F02282.EPS
F0229.EPS