Adjusting For Zero Shift; Set Zero Shift; Flow Calculations - Emerson FloBoss 103 Instruction Manual

8.3 Adjusting for Zero Shift

Revised August-2017
If desired, use the zero shift procedure after calibrating the differential
pressure input for the FB103. The FB103 calibrates differential pressure
without applying line pressure to the sensor. When you connect the
sensor back to the process after calibration, a shift in the differential
pressure can occur due to the influence of the line pressure. You can
cancel out this effect with a zero shift adjustment.
To check or adjust for zero shift, leave the sensor by-pass valve open
(to simulate a no-flow condition), with either line pressure or a normal
operating static pressure from the calibrator applied to the sensor. This
applies the same pressure to both sides of the differential pressure
diaphragm to give a zero differential pressure reading.
Perform the following steps:
1.
Ensure ROCLINK 800 software is connected to the FB104 and is
running the calibration procedure.
2.
If you already released the meter inputs from the freeze condition,
click Freeze. This displays the Meter Calibration window (see
Figure 8-11).
3.
Under the Diff Press input, click Zero Shift. The Set Zero Shift
window displays.
4.
Review the value in the Live Reading field. If it is not zero, you
need to perform a zero shift correction.
5.
Click Set Zero Shift to adjust the Zero Shift. The value in the Live
Reading field should change to zero.
6.
Click Done. The Meter Calibration window displays.
7.
Click OK to close the Meter Calibration window, cancel the freeze
values, and enable the FB100 to begin using live readings for the

flow calculations.

Calibration
FloBoss 103/104 Instruction Manual
Figure 8-10. Set Zero Shift
8-7