Chandler Engineering AMETEK 7200, Instruction Manual

Page: 41 / 77

SECTION 4 – CALIBRATION 4 - 1
Section 4 - Calibration
Note: The pressure transducers, RTDs, and flow meters were all calibrated by their
respective manufacturers. See their calibration sheets in the accompanying
document package. The CHA in
strument’s measurements of pressures ,
temperatures, and flow rates (using those transducers, RTDs, and flow meters)
were all calibrated at Chandler Engineering.
Pressure Calibration
The three pressure transducers used by the Model 7200 CHA are very-high-accuracy (+/-
0.1% of Full Scale) transducers. These transducers output a linear 0-5VDC signal
corresponding to 0-1000 psig. This signal is read by the data-acquisition module and the
CHA-Control software converts this voltage to a pressure value according to the calibration
scaling entered on the calibration screen for that transducer. The procedure is identical for all
three pressures.
Figure 13 - Pressure Calibration
There are three methods of calibration:
1. Auto Calibrate (Recommended): Let the software use the Shunt Calibration feature
of the transducer to automatically calibrate it and scale the conversion from voltage to
pressure.
2. Span and Zero Calibration: Apply exactly known pressures to the transducer and
the software will calculate the Slope and Intercept.
3. Manual Entry: Manually enter a Slope and Intercept.