Definition of sensor

A sensor is a detection device that can feel the information being measured, and can transform the sensed information into electrical signals or other required forms of information output according to a certain rule to meet the transmission, processing, storage, and display of information, Recording and control requirements. It is usually composed of sensitive components, conversion components, signal conditioning and conversion circuits and other auxiliary components. The sensitive element receives the measured and outputs other quantities that are in a determined relationship with the measured, the conversion element converts the other quantities from the sensitive element into electrical signals suitable for transmission and measurement, the electrical signals suitable for output and measurement are converted into useful electrical signals that can be displayed, recorded, processed and controlled by the signal conditioning and conversion circuit, and finally the useful electrical signals are transmitted to other devices and communicated.

Composition of the sensor

Sensitive element: an element that directly feels the measurement and outputs a physical quantity that is in a definite relationship with the measurement.
Conversion element: the core element of the sensor, with the output of the sensitive element as the input, the perception of non-electricity is converted into electrical signal output. The conversion element itself can be used as an independent sensor, called an element sensor.
Transformation circuit: the electrical signal output by the sensing element is converted into a useful electrical signal for processing, control, recording and display.
Auxiliary power supply: conversion components and conversion circuits generally also need auxiliary power supply.