<6. Operation>
6-3
IM 01C25W05-01EN
Since the degree of zero adjustments varies with
the screw turning speed, turn the screw slowly for
fine adjustment and quickly for coarse adjustment.
F0604.ai
Zero-adjustment screw
High pressure side transmitter (master)
Figure 6.4 Zero-adjustment Screw
6.3 Starting Operation
The transmitter starts operating as soon as
zero point adjustment is completed. Follow the
procedure below.
1. Confirm the operating status. If the output
signal exhibits wide fluctuations (hunting) due
to periodic variation in the process pressure,
use the HART configuration tool to dampen the
transmitter output signal. Confirm the hunting
using a receiving instrument or the integral
indicator, and set the optimum damping time
constant.
2. After confirming the operating status, perform
the following:
IMPORTANT
• Remove the HART configuration tool from
the terminal box, and confirm that none of
the terminal screws are loose.
• Close the terminal box cover and the
amplifier cover. Screw each cover in tightly
until it will not turn further.
• There are two covers that must be locked on
the ATEX Flameproof type transmitters.
An Allen head bolt (shrouding bolt) under the
edge of each cover is used to lock the cover.
When the shrouding bolt is driven
counterclockwise with an Allen wrench, the
bolt rotates upward and locks the cover.
(See page 7-3.) After locking the covers,
confirm that they are secure and cannot be
opened by hand.
• Tighten the zero-adjustment cover mounting
screw to secure the cover.
6.4 Shutting Down Operation
To shut down operation, turn off the power.
NOTE
Whenever shutting down the transmitter for a
long period, detach the transmitter from the tank.
6.5 Venting or Draining
Transmitter Process-
Detector Section
If condensate (or gas) collects in the transmitter
process-detector section, the measured pressure
may be in error. If a flushing connection ring is
mounted, loosen the ring’s drain (vent) screw to
completely drain (vent) the liquid (gas). Then, re-
tighten the drain (vent) screw.
IMPORTANT
Since draining condensate or bleeding off gas
gives the pressure measurement disturbance,
this should not be done when the loop is in
operation.
