A sensor is a device that measures physical input from its environment and converts it into data that can be interpreted by either a human or a machine. Most of them are electronic (the data is converted into electronic data). But some are more simple, such as a glass thermometer. Which presents visual data. Temperature, humidity and pressure sensors are the most commonly used for HVAC and building equipment applications. Temperature detectors can monitor ambient conditions as well as liquids and gases that are used to heat and cool the environment. Pressure controllers and transducers can operate in the same way to provide efficiency.
There are two types of electronic sensors: analog and digital. Analog detectors convert physical data into an analog signal. Analog sensors are much more precise than digital sensors, which are limited to a finite set of possible values.