Classification of sensors
Sensors can be divided into temperature sensors, pressure sensors, photosensitive sensors, sound sensors and other types according to the measured physical quantities. Among them, the most common sensors are temperature sensors and pressure sensors.
Principle of temperature sensor
Temperature sensor is a kind of sensor that can measure the temperature of an object, and its measuring principle is to use thermoelectric effect. When two metals are connected, electrons will flow from the metal with strong conductivity to the metal with weak conductivity, forming a potential difference. This phenomenon is called thermoelectric effect. According to the principle of thermoelectric effect, we can make a thermocouple and measure the temperature of an object through the potential difference of the thermocouple.
Principle of pressure sensor
Pressure sensor is a kind of sensor that can measure the pressure of an object, and its measuring principle is to use strain effect. When an object is under pressure, it will produce strain, that is, its shape and size will change. According to the principle of strain effect, we can make a strain gauge and measure the pressure of the object through the change of the strain gauge.
Application of sensor
Sensors are widely used, for example, in the industrial field, pressure sensors can be used to measure the pressure and load of mechanical equipment, and temperature sensors can be used to measure the temperature of mechanical equipment, so as to judge whether the mechanical equipment works normally. In the field of medical diagnosis, temperature sensor can be used to measure the temperature of human body, so as to judge whether human body has a fever.
Operating steps of sensor
1. Determine the physical quantity to be measured and select the corresponding sensor;
2. Install the sensor on the measured object;
3. Connect the sensor with the circuit, and process and output the electric signal;
4. Judge and process according to the measurement results.
Development trend of sensors
With the continuous progress of science and technology, the application scope and performance requirements of sensors are also constantly improving. Future sensors will have higher accuracy, smaller size, lower power consumption and more functions. For example, biosensors can measure biological indicators in the human body, thus realizing real-time monitoring and health management; Smart sensors can be interconnected through wireless communication technology to realize the construction of smart homes and smart cities.