Manual

Form 921 (03.13) ©SOR Inc.
3/8
Calibration
Two calibration screws (zero and span) are located underneath the adjustment cover. (See
) Loosen the cover screws slightly (do not remove) and rotate the cover to reveal the
adjustment screws.
Numbers on the enclosure identify the adjustment screws: 1, 2 and 3.
Adjustment #1: Zero
Adjustment #2: Span
Adjustment #3: Not used
Unless specified otherwise, the transmitter is factory calibrated to 1 VDC @ 0 psi and 5
VDC at the top of the adjustable range specified on the nameplate.
Calibration Procedure
The zero and span calibration procedure should be performed under ambient process
temperature conditions.
A pressure source with a calibrated reference gage, a voltmeter and a DC voltage supply are
required. (See
) Note the adjustable range on the instrument nameplate. For both zero
and span adjustments, turn the adjustment screw clockwise to increase, counterclockwise
to decrease.
 Connect the transmitter as shown in . The case ground must be connected to the
earth ground.
 Apply pressure at which 1 VDC output is desired. (Zero may be adjusted + 10% of the
Upper Range Limit.)
 With the pressure source steady at the desired zero level, rotate the zero adjustment
(#1) for a 1 VDC indication on the voltmeter.
 Apply pressure at which 5 VDC output is desired. The span may be adjusted from 20 to
100% of the upper range limit specified on the nameplate. (Maximum turndown is 5:1.)
 With the pressure source steady at the desired span level, rotate the span adjustment
(#2) for a 5 VDC indication on the voltmeter.
 Repeat Steps 2 through 5 as needed if offsetting 1 VDC from the normal zero point.