YOKOGAWA DpharpEJX vigilantplant EJX Series - Functions Relating to Static Pressure

IM 01C25T01-01E
3-27
3. OPERATION
3.5.17 Capillary Fill Fluid Density Compensa-
tion
For transmitters with diaphragm seals, this function is
used to compensate the zero shift caused by the
ambient temperature effect on the capillary tubes.
The following equation indicates the relationship
between the calculated output value and the compen-
sating constant K (%/C) with the measured ambient
temperature at the capsule module.
Compensated output#output"K!Tamb
(1) Temperature Compensation Mode Setup
When using this function, set T.Z. Cmp mode to ON
to enable or OFF to disable. To set to ON, follow the
procedure below.
F0351.EPS
(ENTER)
EJX:
T.Z. Cmp mode
Off
Off
On
HELP DEL ESC ENTER
Select On, and press ENTER (F4).
1. Device setup
4. Detailed setup
2. Signal condition
T.Z. Cmp menu
1. T.Z. Cmp mode
Example: Set the temperature compensation mode to ON.
EJX:
T.Z. Cmp menu
1 T.Z. Cmp mode On
2 Temp Zero
HELP SEND HOME ENTER
Press SEND (F2) to send the data
to the transmitter, then check to
confirm that disappears.
(SEND)
SEND
1
2
(2) Zero Shift Compensation Setup
Obtain the K compensating value from the equation (a)
below, and enter the value to Temp Zero.
K=
– h×B
×100
................
(a)
Span
where,
B: Constant value of fill fluid (See Table A.)
span: |URV–LRV|
h: Distance from high pressure side to low
pressure side (m)
EJX118A: Distance from high side of dia-
phragm seal to low side of diaphragm seal.
EJX438A: Distance from diaphragm seal (high
side) to position of transmitter (low side).
Transmitter
L
h
0
H
(")
 EJX118A
F0353.EPS
h
h
L
L
H
Transmitter
Transmitter
0
(")
()
 EJX438A
Note: When the transmitter is positioned lower than the
diaphragm seal part, the value of “h” must have a
negative sign ().
F0354.EPS
1. Device setup
4. Detailed setup
2. Signal condition
T.Z. Cmp menu
2. Temp Zero
Example: Enter K value obtained from the equation (a).
A value haivng up to 3 decimal places may be
specified.
When h#"3 m, Fill fluid code A, span#15 kPa,
K#("3)!0.00745$15!100#0.149
EJX:
Temp Zero
0.000 %/degC
-0.149
ESC ENTER
1
2
(ENTER)
HELP DEL
Enter 0.149 and press ENTER
(F4).
‘ 0.149 ’
EJX:
T.Z. Cmp menu
1 T.Z. Cmp mode On
2 Temp Zero
HELP SEND HOME ENTER
Press SEND (F2) to send the data
to the transmitter, then check to
confirm that disappears.
(SEND)
SEND
Note 1: The function is performed using a built-in temperature sensor
in the transmitter body. The temperature deviation between
the transmitter body and capillaries should be minimized to
achieve optimal performance of the function.
Note 2: When the span changes, reenter the newly obtained value of
K to Temp Zero.