15) zero point adjustment – Yokogawa EJA118 User Manual
Page 43
 
IM 1C22H1-01E
7-14
7. BRAIN TERMINAL BT200 OPERATION
Note that changing the higher range value does not
cause the lower range value to change but does change
the span.
• Example 2: When the higher range value is to
be changed to 10 kPa with the
present setting of 0 to 30 kPa, take 
the following action with an input 
pressure of 10 kPa applied.
FEED
NO
OK
SET
 H11:AUTO HRV
 10.000 kPa
DATA
DIAG
PRNT
ESC
PARAM
 H10:AUTO LRV
 0 kPa
 H11:AUTO HRV
 10.000 kPa
 H60:SELF CHECK
 GOOD
ESC
SET
 H10:AUTO HRV
 30 kPa
 + 30
The lower range value is not
changed, so the span changes.
Parameter C22 is changed at the
same time.
Press the key twice.
The higher range value is changed
to 10 kPa.
Press the (OK) key.
F0732.EPS
(15)
Zero Point Adjustment
(J10: ZERO ADJ, J11: ZERO DEV,
J20: EXT ZERO ADJ)
The DPharp supports several adjustment methods.
Select the method best suited for the conditions of your
application.
Note that output signal can be checked by displaying
parameter 
A10:OUTPUT (%)
on the BT200.
Adjustment Method
Description
Using the BT200
Set the present input to 0%.
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 accuratly reads output 
currents.
Adjust output to the reference value 
obtained using other means. 
Adjust for 0% output at input level of
0%.
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.
T0710.EPS
(a) Follow the procedure below when setting the
present output to 0% (4 mA).
FEED
NO
OK
SET
 J10:ZERO ADJ
 0.0 %
CLR
ESC
SET
 J10:ZERO ADJ
 0.0 %
 + 000.0
Press the key twice.
Zero adjustment is completed.
Press the (OK) key.
F0733.EPS
Output is 0.5%.
A10:OUTPUT (%) 
 0.5 %
Output is 0%.
A10:OUTPUT (%) 
 0.0 %
(b) In tank level measurement, if the actual level
cannot be brought to zero for zero adjustment, then
the output can be adjusted to correspond to the
actual level obtained using another measuring
instrument such as a glass gauge.
100%
Present level
45%
Present level: 45%
Present output: 41%
0%
DPharp
F0734.EPS
(b)-1 Follow the procedure below to use
J10: ZERO
ADJ
.
CLR
ESC
SET
 J10:ZERO ADJ
 0.0 %
 + 040.0
Enter the present actual level, 40%.
Press the key twice.
The output is changed to 40%.
F0735.EPS
Present output is 41.0%.
A10:OUTPUT (%) 
 41.0 %
A10:OUTPUT (%) 
 40.0 %