3-38
Chapter 3 Starting and Stopping this Device
3-7
Zero Adjustment Based on Actual Level During Liquid Level Measurement
To adjust the zero point while they liquid level is being measured, without actually draining the
liquid to the zero level, it is possible to make adjustment using an output value correlated with the
actual level as measured by a level gauge (etc.). In conjunction with this operation manual, see the
operation manuals for the respective communicators.
CommStaff Operation Manual: Section 3-3
HART Communicator Operation Manual: Section 3-2-3
3-8 Zero/Span Adjustment Based on Range-Equivalent Input Pressure
By applying the pressure corresponding to the desired range to the transmitter, the lower range
value (LRV, the input pressure during 0% output) and upper range value (the input pressure during
100% output) can be set to values that correspond to the actual pressure. The lower range value
and upper range value are automatically set using the desired liquid level or input pressure, and
the zero/span adjustment can be completed. In conjunction with this operation manual, see the
operation manuals for the respective communicators.
CommStaff Operation Manual: Section 3-2
HART Communicator Operation Manual: Section 3-2-3
(1) Notes for Zero Adjustment
When performing zero adjustment in a case where the upper range value will exceed the upper
sensor limit (USL), note that there are differences in behavior between HART 5 and HART 7.
- HART5
The present liquid level or input pressure is set as the lower range value. The upper range value is
set while maintaining the span unchanged.
- HART7
The present liquid level or input pressure is set as the lower range value. The upper range value is
cut off at the upper sensor limit. Since the new upper range value may not be appropriate, change
it as necessary.
Table 3-2. Setting Range for Each Model Number
model JT LSL USL
910 -1kPa 1kPa
920 -100kPa 100kPa
930, 931, 940 -100kPa 700kPa
960, 961, 980 -0.1MPa 14MPa
To Next Page
Loading...