This is pressure sensor signal conditioning circuit. It is simple and inexpensive circuit because it has small geometry and simple pressure sensor. It just uses a single Operational Amplifier. This circuit obtain power from from 3-V battery. To work properly this circuit must work in  0 C to 50 C temperature range. Here is the schematic diagram :

Pressure Sensor Signal Conditioning Circuit with Single Op Amp circuit schematic

This simple circuit is used to amplify the pressure sensor’s output voltage to levels that suitable for subsequent digital processing and A/D conversion. ROT is offset trimmer, C1 is used to limit the band. The gain setting of this circuit is RFX/RGX. ±VB is sensor bridge output. [Source: Texas Instruments Application Report]