A sensor, also called a transducer, detector or detector, etc., refers to a measuring device that can sense a specified measured value and convert it into an electrical quantity output according to a certain rule, usually composed of a sensitive component and a conversion component. Among them, the sensitive component means that the sensor can directly feel the measured part.

First, the composition of the sensor

In general, the sensor consists of a sensitive component and a conversion component. However, it is often difficult to directly display, record, process, and control the amount of power output from the conversion component. In this case, it needs to be further converted into an electrically usable signal, and the part of the sensor that performs this function is called a measurement circuit. For example, the measuring circuit in the strain gauge pressure sensor is a bridge circuit, which can convert the resistance value change of the strain gauge output into a voltage or current change, and can be recorded after being amplified to display the operation of the meter. With the application of semiconductor components and integrated circuit technology in sensors, the measuring circuit of the sensor can be installed in the housing of the sensor and the cargo sensitive components are integrated on the same chip. Therefore, the measuring circuit and the required power supply should be composed of sensors. portion. The selection of the measurement circuit depends on the type of conversion element, a bridge circuit, a pulse width modulation circuit, a high input impedance circuit, and the like which are often employed.

In summary, the sensor is generally composed of four parts: a sensitive component, a conversion component, a measuring circuit, and an auxiliary power supply. However, some sensors may combine sensitive components and conversion components, and some sensors may not require an auxiliary power supply.

Second, the classification of sensors

Sensors are generally designed and manufactured according to certain manufacturing processes using certain effects, laws or principles of physics, chemistry, and biology. A sensor designed and manufactured by a certain principle can measure a variety of non-electrical parameters at the same time, and sometimes a non-electricity can be measured by several different sensors, so the sensor can simultaneously measure a variety of non-electrical parameters, and sometimes a non-electrical quantity There are several different sensor measurements, so there are many ways to classify the sensor. Generally, it can be classified according to the following methods.

1. Classified by physical quantity to be measured

This method is classified according to the nature of the measured physical quantity, such as the measured physical quantity is temperature, pressure, flow, displacement, toot, and the like. The corresponding sensors are called temperature sensors, pressure sensors, displacement sensors, speed sensors, and so on.