The temperature sensor converts the relationship between various physical properties of materials and temperature into effective output signals. As the core component of the thermometer, there are many types. According to its measurement method, it can be divided into two categories: contact type and non-contact type. According to the characteristics of its material and device, it can be divided into thermal resistance type and thermocouple type. The current temperature sensor is very small, so it has great applications in many aspects of actual production, which brings a lot of convenience and practicality to our life.