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b) Select an approved calibration system in accordance with the range and output option of the transducer
being calibrated.
Observe all precautions given in the calibration technical manual and in Navy
precautions for forces afloat OPNAVINST 5100.
Air or nitrogen under pressure is used in the operation of the pressure transducer
calibration system. Severe injury may result if personnel fail to observe safety
precautions.
To prevent injury, insure all connections are properly made before applying air or
nitrogen pressure.
b) To gain access to the ZERO and SPAN adjustments, loosen (DO NOT REMOVE) the two screws located
on the top of the transducer and rotate the ZERO/SPAN ACCESS COVER until the SPAN and ZERO
adjustments potentiometers are exposed (Figure 2-1).
c) Apply 28 V dc + 4.5Vdc power to the transducer.
d) Prepare the transducer for ZERO pressure check as follows:
1) For gauge pressure transducers, vent the pressure port connection (MS16142) to atmosphere so the
transducer will sense zero psig in accordance with the calibration system technical manual.
2) For absolute and compound pressure transducers, use a vacuum pump to obtain 30" Hg. vacuum at
the pressure port connection in accordance with the calibration system technical manual.
3) For differential pressure transducers, vent both the high and low side pressure port connections
(MS16142) to atmosphere so the transducer will sense zero psid in accordance with the calibration
system technical manual.
e) Verify that the transducer output indication is 4.00 + 0.16 mA dc (0.000 + 0.050 V dc for voltage output
option). Perform ZERO adjustments to obtain the transducer's output as specified. ZERO is accomplished
by a screwdriver adjustment of the ZERO potentiometer located under the ZERO/SPAN ACCESS
COVER. See Figure 2-1 for potentiometer access.
To prevent equipment damage, do not exceed the pressure rating of the transducer when
calibration is performed.
f) If the range is exceeded within the overpressure range of MIL-T-24742 (SH), verify the zero calibration in
accordance with step d). before proceeding. If the range is exceeded beyond the overpressure
specification, unit may not be serviceable. Verify calibration before returning to service.
WARNING
CAUTION
6-4
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