A sensor or transducer is a device that converts one type of energy to another – usually electric. They are used for various purposes, including measurement or information transfer. Generally speaking, a sensor or transducer is a device that converts a signal from one to another. Let’s go through transducer characteristics that describe the performance of sensors. One of the characteristics that describe the functional relationship between physical input and electrical output is the Transfer Function, which shows the relationship between the input and output signal. Depending on the details of this characteristic, it may be a complete description of sensor characteristics. The transfer function may be used as a calibration curve. For instance, let’s take an example of the infrared temperature sensor.