Yokogawa EJA530A - Manual (Page 31)

IM 01C21F01-01E 7-4
7. OPERATION
7.5 Setting the Range Using the
Range-setting Switch
With actual pressure being applied to the transmitter,
the range-setting switch (push-button) located on the
optional /E integral indicator plate and the external
zero-adjustment screw allow users to change (re-range)
the low- and high-limit values for the measurement
range (LRV and HRV) without using BT200. How-
ever, other changes in the display settings (scale range
and engineering unit) for the integral indicator requires
BT200.
Follow the procedure below to change the LRV and
HRV settings.
[Example]
Rerange LRV to 0 and HRV to 3 MPa.
1) Connect the transmitter and apparatus as shown in
Figure 9.3.1 and warm up for at least five minutes.
2) Press the range-setting push-button.
The integral indicator then displays “LSET.”
3) Apply a pressure of 0 kPa (atmospheric pressure) to
the transmitter. (Note 1)
4) Turn the external zero-adjustment screw in the
desired direction. The integral indicator displays the
output signal in %.
(Note 2)
5) Adjust the output signal to 0% (1 V DC) by rotating
the external zero-adjustment screw. Doing so
completes the LRV setting.
6) Press the range-setting push-button. The integral
indicator then displays “HSET.”
7) Apply a pressure of 3 MPa to the transmitter. (Note 1)
8) Turn the external zero-adjustment screw in the
desired direction. The integral indicator displays the
output signal in %.
(Note 2)
9) Adjust the output signal to 100% (5 V DC) by
rotating the external zero-adjustment screw. Doing
so completes the HRV setting.
10) Press the range-setting push-button. The transmitter
then switches back to the normal operation mode
with the measurement range of 0 to 3 MPa.
Note 1: Wait until the pressure inside the pressure-detector section
has stabilized before proceeding to the next step.
Note 2: If the pressure applied to the transmitter exceeds the previous
LRV (or HRV), the integral indicator may display error
number “Er.07” (In this case, the output signal percent and
“Er.07” are displayed alternately every two seconds).
Although “Er.07” is displayed, you may proceed to the next
step. However, should any other error number be displayed,
take the appropriate measure in reference to Subsection
8.5.2, “Errors and Countermeasures.”
IMPORTANT
• Do not turn off the power to the transmitter
immediately after completion of the change in
the LRV and/or HRV setting(s). Note that
powering off within thirty seconds after setting
will cause a return to the previous settings.
• Changing LRV automatically changes HRV to
the following value.
HRV = previous HRV + (new LRV – previous LRV)
• If the range-setting push-button and external
zero-adjustment screw are not touched during a
range-change operation, the transmitter auto-
matically switches back to the normal operation
mode.
F0707.EPS
Integral indicator
Range-setting switch
(Push-button)
Note : Use a thin bal which
has a blunt tip, e.g.,
a hexagonal wrench,
to press the range-
setting push-button
Figure 7.5 Range-setting Switch