Question

Strain gauges are constructed with Germanium chips because Germanium:
1. has a strong Hall effect
2. is crystalline in nature
3. can be doped
4. has piezo-electric property

Answer 1

Correct Answer - Option 4 : has piezo-electric property

• Metal strain gauge is a passive transducer that converts applied strain to a resistance change. A semiconductor strain gauge is a special type of strain gauge based on the Piezoresistive effects of silicon or germanium.
• The effect of metal strain gauge is caused by the geometric deformation of the resistor, whereas piezoresistance effect is caused by the change in resistivity of the material.
• The change in resistance of a strained (or stressed) germanium or silicon filament is much larger than that of a metal strain gauge.
• Therefore, strain gauges are constructed with Germanium chips.