Depends what kind of sensor you are asking about. Piezo properties are used in quite a few sensors.
Measure the impedance with a gain-phase analyzer if you have access to one.
For an acoustic sensor operating at 20 Hz, a low-frequency sensor platform such as a piezoelectric sensor would be most appropriate. Piezoelectric sensors are well-suited for low-frequency applications like 20 Hz due to their sensitivity and ability to detect small vibrations at such frequencies. Additionally, piezoelectric sensors offer good signal-to-noise ratio and durability, making them ideal for continuous monitoring applications.
A knock sensor is a piezoelectric device that senses the knocks produced in the engine. The knock sensor tells de computer to retard the timing in order to prevent piston damage and/or blown head gaskets.
Like this: (piezoelectric-crystal)
an 02 sensor is a piezoelectric sensor which creates a voltage based on the amount of oxygen present in the exhaust. this lets the engines computer know how rich or lean the engine is running and adjust accordingly
how sound sensor work
The detonation sensor ( knock sensor ) really cannot be checked by the home mechanic it is either good or bad. It consists of a pressure sensing piezoelectric element that converts pressure differences into electrical signals that can be read by the computer.
Piezoelectric infrared radiation detectors made of triglycine sulfate can convert infrared radiation into detectable electrical signals. When infrared radiation hits the crystal structure of the triglycine sulfate, it creates an electric charge due to the piezoelectric effect, which can then be measured as a voltage signal. This allows the detector to sense and quantify the presence of infrared radiation.
The piezoelectric microphone was invented in 1917 by Aleksandr W. Gurvich and his colleagues. They discovered the piezoelectric effect in Rochelle salt crystals, leading to the development of the first piezoelectric microphone.
To test a piezoelectric sensor, you can apply a known force or pressure to the sensor and measure the corresponding electrical output. This can be done using a multimeter or an oscilloscope. You can also check for continuity in the sensor's wiring and inspect for any physical damage that may affect its performance.
Piezoelectric transducers can be utilized to measure pressure or weight by converting mechanical stress into an electrical charge. When a human stands on a piezoelectric sensor, the pressure applied generates a voltage proportional to the weight. This voltage can then be measured and calibrated to provide a direct weight reading. Such sensors are often employed in scales or pressure-sensitive mats for applications in health monitoring and fitness tracking.
•many EFI engines have knock sensor.the knock sensor may be mounted in the block cylinder head or intake manifold. •A piezoelectric sensing element is mounted in the knock sensor and the resistor is connected parallel to the sensing elements. when the engine detonates, a vibration occurs in the engine. •The piezoelectric sensing element changes the vibration into an analog voltage and this signal is sent to the knock sensor module. •The knock sensor module changes the AC voltage signal into a digital voltage and sends this signal to the ECU. When the ECU receives this signal, it reduces the spark advance to prevent detonation. •Reference book: Automotive technology