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Locate the supplied jumper plug and insert over the two terminal header pins above the
potentiometers. Check that the output is approximately 15 mA - 17 mA or close to the value
printed on the supplied customer data sheet. On models constructed after April 1998, the value
is located on the transducer label.
Diagnostic Shunt (0.1-5.1 Vdc output)
Calculate the slope of output current vs. pressure:
Slope = Vdc output voltage / pressure of full span
The elevated zero at atmospheric pressure:
Elevated Zero = 0.1 Vdc + (slope) x (absolute value of full vacuum pressure)
The following is an example for a Vac to 30 psig factory calibrated as -14.7 psig to 30 psig:
Zero (at -14.7 psig) = 0.1 Vdc
Full Scale (at 30 psig) = 5.1 Vdc
Slope = (5.1 Vdc - 0.1 Vdc)/(14.7 psig + 30 psig) = 5Vdc/44.7 psig
The reading at 0 psig or atmospheric pressure is:
Elevated Zero =0.1 Vdc + (5Vdc/44.7 psig) x (14.7 psig) = 1.744 Vdc
Locate the supplied jumper plug and insert over the two terminal header pins above the
potentiometers. Check that the output is approximately 3.5 Vdc - 4.2 Vdc. or close to the value
printed on the supplied customer data sheet. For units constructed after April 1998, the value is
located on the transducer label.
If field calibration has been attempted as described in Section IV (Field Calibration), the
shunt value as supplied with the transmitter may no longer be valid. Always record a new
shunt value when making field adjustments.
pg. 4-3
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