Teledyne 760 PLUS instruction manual Operating Information, General

3. Operating Information

This section contains information on operating the PIEZO Resistive Transducer in any of its various configurations. Refer to the appropriate section for information on the mode in use.

3.1. General

The piezoresistive transducer is shown schematically in figure 3-1. Basically the membrane contains an ion implanted resistive element that is part of a Wheatstone bridge circuit shown in figure 3-2. The underside of the transducer has been evacuated and sealed to produce a deflection of the membrane the magnitude of which is a function of the differential pressure (ΔP) across the membrane. The resistance of the membrane element changes with that ΔP and thus changes the bridge output.

PIEZO RESISTOR	DIOXIDE
DEPLETION
REGION
	SILICON
	CHIP
VB	Fig 3-1

R+ΔR	R-ΔR
R-ΔR	R+ΔR
	VOUT

Fig 3-2

Manual: 147-082010_HPM-760-Plus-Vacuum-Gauge Page 8 of 16