Explanation:

Instrumentation systems use different types of transducers to convert physical quantities such as temperature, pressure, strain, etc into an electrical signal. The electrical signal is then amplified, processed, and displayed on a suitable output device. However, some transducers require a high input impedance preamplifier for proper measurements. Piezoelectric transducers are one such example.

Piezoelectric Transducers:

A piezoelectric transducer is a device that converts mechanical energy into electrical energy. It is based on the principle of piezoelectricity, which states that certain materials (such as quartz, ceramics, etc.) produce an electric charge when subjected to mechanical stress. Piezoelectric transducers are used in a wide range of applications such as accelerometers, pressure sensors, and vibration sensors.

High Input Impedance Preamplifier:

A preamplifier is an electronic device that amplifies small electrical signals to a level where they can be further processed. In the case of piezoelectric transducers, the output signal is small and requires amplification. However, the input impedance of the amplifier must be high to avoid loading the transducer, which can affect the accuracy of the measurement. The input impedance of the preamplifier should be at least 10 times higher than the output impedance of the transducer to avoid any errors.

Conclusion:

In conclusion, piezoelectric transducers require a high input impedance preamplifier for proper measurements. The preamplifier must have a high input impedance to avoid loading the transducer, which can affect the accuracy of the measurement. Therefore, it is important to select the appropriate preamplifier for the specific type of transducer being used in an instrumentation system.