A sensor is a device or apparatus capable of detecting a specified physical quantity and converting it-according to a specific rule-into a usable input signal. Simply put, a sensor is a device that converts a non-electrical quantity into an electrical quantity.
Sensors typically consist of three main components: a sensing element, a conversion element, and a measurement circuit.
The sensing element refers to the component capable of directly detecting (or responding to) the quantity being measured; specifically, it converts the measured quantity-via the sensor's sensing element-into a non-electrical quantity or other form of energy that bears a definitive relationship to the original measured quantity.
The conversion element, in turn, converts the aforementioned non-electrical quantity into an electrical parameter.
The function of the measurement circuit is to process the electrical parameter received from the conversion element, converting it into a measurable electrical quantity-such as voltage, current, or frequency-to facilitate subsequent display, recording, control, and data processing.
