Precision Measurement Engineering, Inc.
Precision Measurement Engineering, Inc.
The pressure sensor is a PAA-10 supplied to PME by Keller PSI. For more information, view the manufacturer's data sheet. Maximum sensor pressure varies depending upon the depth specified for the SCAMP; 10 bar is typical. The sensor consists of a stainless steel diaphragm that transmits pressure via a silicone oil filled cavity to a thin diaphragm chemically milled on a silicon substrate. Strain sensitive resistors are diffused into this diaphragm in a bridge configuration. Applied pressure causes the values of these resistors to shift in a linear manner.
The pressure channel circuitry is simply a constant current source supplying the sensor bridge and a gain of 100 D.C. differential amplifier connected across the sensor bridge. This circuit is located on the 5026 Main Analog circuit board.
The Depth Channel
Calibration graphs shows a typical pressure calibration. Both the slope and the zero
intercept will vary from sensor to sensor.