Calibration; Equipment Required; Calibration Procedure - Emerson Fisher 546NS Instruction Manual

546NS Transducer
June 2021
Figure 4. Zero and Span Adjustments (Cover Removed)
The zero adjustment is used to set the output pressure so that it corresponds to the proper value of the input signal.
For example, if the output range is 0.2 to 1.0 bar (3 to 15 psig) and the input range is 4 to 20 mA DC and the unit is
direct‐acting, use the zero adjustment to set the output pressure at 0.2 bar (3 psig) when the input signal is 4 mA DC.
Use the span adjustment to set the output pressure span so that full output pressure change results for a full change in
the input signal. In this example, the output pressure change would be 0.8 bar (12 psi). Thus, the output pressure
should start at 3 psig and increase to 1.0 bar (15 psig) as the input signal is changed from 4 to 20 mA DC.
A span adjustment will affect the zero. Therefore, follow any span adjustment with a zero adjustment. Provide a
suitable gauge to measure the pressure.
CAUTION
If the transducer is not used as specified in this instruction manual, the protection provided by the equipment may be
impaired.

Calibration

Equipment Required

Choose a current or voltage source that is capable, without switching ranges, of driving the transducer through its
entire input range. Switching ranges on a current source will produce spikes or mid‐scale reverses in the input signal
presented to the transducer, causing errors.

Calibration Procedure

Note
The following calibration procedure is for a 546NS transducer with a 4 to 20 mA DC input signal range and a 0.2 to 1.0 bar (3 to 15
psig) output range. Calibrate transducers with other inputs and outputs in a similar manner.
10
SPAN ADJUSTMENT
W5391/IL
ZERO ADJUSTMENT
Instruction Manual
D103425X012