<3. Operation>
3-15
IM 01C25T03-01E
a. Zero Trim (J11: P ZERO ADJ, J15: P ZERO
DEV, J55: EXT ZERO ADJ)
The transmitter supports several adjustment
methods. Select the method best suited for the
conditions of your application.
Adjustment
Method
Description
Using the BT200
Set the present input to 0%.
Adjust for 0% output at input level
of 0%.
Adjust output to the reference
value obtained using other means.
If the input level cannot easily
be made 0% (because of tank
level, etc.), adjust output to the
reference value obtained using
other means, such as a sight
glass.
Using the
external zero-
adjustment
screw
Adjust zero point using the zero-
adjustment screw on the transmitter.
This permits zero adjustment without
using the BT200. Accurately adjust
the output current to 4 mA DC or
other target output value using an
ammeter that accurately reads output
currents.
When using BT200, the output signal can be
adjusted either in % or pressure unit. The unit
can be selected by the parameter J09: ADJ UNIT.
Output signal can be changed by displaying
parameter A10: OUTPUT for % or J10: OUTPUT
for pressure unit.
This section discribes the zero adjustment
procedure by using the pressure unit.
a-1. Zeroing
Setting the parameter J11: P ZERO ADJ carries
out the zero adjustment and automatically sets the
applied “0” input values to the transmitter’s output
value of zero, keeping the span constant. Use this
setting when the LRV is known to be 0 kPa.
FEED
NO
OK
SET
J11:P ZERO ADJ
0.00000 kPa
CLR
DEL
ESC
SET
J11:P ZERO ADJ
0.00000 kPa
+ 0
A pressure of 0 kPa is applied.
Press the key twice
after the pressure has become
stable.
Zero adjustment is completed.
Press the (OK) key.
F0336.ai
Transmitter measures pressure of
0.03585 kPa.
Transmitter measures pressure of
0.00000 kPa.
A11:PRES
0.03585 kPa
A11:PRES
0.00000 kPa
a-2. Level Adjustment
The zero adjustment by the parameter J11: P ZERO
ADJ calibrates the transmitter output corresponding
to the actual tank level. To perform this adjustment,
first use a glass gauge or the like to determine the
actual tank level, then enter the correct data as
shown below.
F0337.ai
25.00 kPa
0.00 kPa
Actual level
13.50 kPa
DPharp span: 0 to 25.00 kPa
Actual level: 13.50 kPa
Transmitter output: 13.83 kPa
DPharp
CLR
DEL
ESC
SET
J11:P ZERO ADJ
0.00000 kPa
+ 045.0
+ 13.5
Enter the present actual level,
13.5 kPa.
Press the key twice.
The measured pressure is
changed to 13.5 kPa.
F0338.ai
Transmitter measures present
pressure of 13.83 kPa.
A11:PRES
13.83 kPa
A11:PRES
13.5000 kPa
