APG PT-400 Pressure Transducer user manual - Manual (Page 5)

Rev. C,4/13 PT-400
5
Automation Products Group, Inc.
APG...Providing tailored solutions for measurement applications
Tel: 1/888/525-7300 • Fax: 1/435/753-7490 • www.apgsensors.com • [email protected]
• Instructions
All units are factory calibrated prior to shipment.
1. Zero Trimming
If it becomes necessary to re-adjust “zero”, this can be accomplished by
adjusting the trimpot marked “Z”. An ideal zero is indicated by an output of
4 mA. (4/20 mA) or 0 (5 VDC, 10 VDC).
A. Remove the protective screw.
B. Ensure that the transducer is at 0 psig or 0 psia (vacuum if absolute)
C. Using a jewelers screwdriver or a suitable instrument, adjust the “Z” pot
until you have 4 mA (4/20 mA) or 0 (5 VDC, 10 VDC) output. Do not make
changes to the Span adjustment (the “S” pot to the right ) as part of the
zero trimming. The Span should only be changed as part of the re-
calibration of a gauge with a known pressure source.
Note: You may also return the transducer to the factory for repair and/or
adjustment.
2. Re-calibration
This procedure requires a known pressure source
of at least ±0.1% accuracy in order to fully utilize the
accuracy potential of the transducer. (If not available,
you can return it to the factory for re-calibration.)
Procedure:
A. Ensure that the transducer is at 0 psig or 0 psia
(vacuum if absolute), and adjust zero as per
instructions in #1.
B. Apply full scale pressure to the pressure port and adjust the span (“S”)
pot until the full scale signal is reached.
C. Re-check zero and re-adjust the zero (“Z”) pot if required.
D. Repeat steps B, and C, until no further adjustment is required.
3. Electrical Information
4/20mA
This device is a 2 wire, loop powered transmitter. A voltage of between 9 and
28 VDC must be maintained at this connection. Completion of the earth or
system ground is recommended for proper circuit protection.
Zero
Adjustment
Span
Adjustment
MAIN PCB ASSEMBLY
S
Z