What kinds of sensors are classified by output parameters?
(1) Resistive type
This type of sensor is a change that will be measured by a sensitive component to a resistance. For example, platinum resistance, copper resistance temperature sensor, is the change of the measured temperature into the resistance value; the thermistor is also the change of the measured temperature into the semiconductor resistance value; the resistance strain sensor is the load to be measured (force , weight), torque, torque, tension, tension, speed, acceleration, etc. are converted into resistance changes of the strain gauge.
The function of the sensor circuit is to convert the change of the resistance into an electrical parameter that is easy to measure, such as using a bridge to convert the resistance into a voltage or current output; and using an oscillating circuit to convert the change in resistance into a frequency.
(2) Capacitive type
This type of sensor is a change that will be measured by a sensitive component to a capacitor. For example, the capacitive line displacement and the angular displacement sensor change the position of the capacitor plate to change the capacitance; the capacitance level gauge converts the liquid level change into the change of the capacitance; the capacitive load sensor changes through the deformation of the elastic body. The relative position of the capacitor plates changes the capacitance; the capacitive vibration sensor, the acceleration sensor, the thickness sensor, the concentricity sensor, and the temperature sensor also convert the measured mechanical vibration, acceleration, thickness, eccentricity, humidity, etc. into capacitance. Corresponding changes.
The function of the sensor circuit is to convert the change in capacitance into a voltage or current signal that is easy to handle, or to convert it into a frequency signal through an oscillating circuit.
(3) Inductive type
This type of sensor is a change in the amount of inductance that will be measured through the sensitive component. For example, the inductive line displacement and angular displacement sensor change the relative position of the iron core with the inductance of the iron core, so that the inductance changes with the measured displacement; the speed and acceleration sensor also change the inductance of the sensor with the change of the speed and acceleration of the iron core; The pressure sensor is characterized in that the elastic element senses the measured pressure and deforms, and the mechanical deformation of the elastic body drives the displacement of the sensor core to change the inductance.
The function of the sensor circuit is to convert the change in inductance caused by the measured change into a form of easy-to-process signal, such as using an inductive bridge to convert the change in inductance into a change in current or voltage; using an oscillating circuit to convert the change in inductance Change in frequency.
(4) Mutual sense
This type of sensor is a change that will be measured by a sensitive component to a mutual inductance. For example, a differential transformer type sensor is measured by the transmission of mechanical components to convert the measured change into the displacement of the differential transformer core, so that the mutual inductance between the excitation winding and the measuring winding changes; the eddy current sensor is measured. The change is converted into a change in the distance between the measuring coil and the measured object, causing a change in the amount of mutual inductance, resulting in a change in the inductance of the measuring coil, and the like.