• Pressure and force transducers (load cell
– consists of elastic material and displacement sensors
– measure quantity (i) strain or (ii) displacement
– grouping: absolute gauge and differential types
Figure 3.51 Diaphragm pressure sensor: (a) flat-type diaphragm, (b) corrugated diaphragm, (c) media of capacitance
• pressure sensor with diaphragm reliable, difficult to make, reproducible
– measure strain with strain gauge or displacement with capacitance
– measurements with capacitance in the bridge circuit are very sensitive and expensive
– Placement and sensor circuit
• bridge circuit for temperature compensation
• Temperature sensitive resistor in both the bridge and the voltage regulator
Figure 3.52 Series of strain gauge pressure sensor tests: (a) unbranded bridges, (b) range of bridges with compensators