SOR 534CR Pressure Transmitter - Manual (Page 5)

Form 903 (03.13) ©SOR Inc. 5/8
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. 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 . Case ground must be connected to earth
ground to ensure EMI/RFI protection.

Apply pressure at which 1 VDC output is desired. (Zero may be adjusted ±10% of the
upper range limit.)

With 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. Span may be adjusted from 25 to
100% of the upper range limit. (Maximum turndown is 4:1.)

With pressure source steady at the desired span level, rotate the span adjustment
slowly (#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.
If interaction occurs, turn zero and span 15 turns counterclockwise. Repeat Steps 2
through 6 above.
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 upper limit of the adjustable range specified on the nameplate.
When calibrating the 534CR, be sure to turn the adjustment magnets slowly.
If the magnets are spun too fast, damage to the unit may occur.