According to the different roles of the instrument in the system, it can be roughly divided into three categories:
1 The signal detection class includes all types of sensors and transmitters. The role is to convert the measured signals into electrical signals or pneumatic signals. We mainly discuss electrical signal sensors here.
A sensor is a device that converts a physical or chemical quantity into an electrical signal that is easy to use.
The classification of sensors can be used to classify sensors from different perspectives: their conversion principles (basic physical or chemical effects of sensor work); their use; the type of their output signals and the materials and processes used to make them.
According to the working principle of the sensor
According to the working principle of the sensor
Can be divided into physical sensors and chemical sensors and biological sensors based on molecular recognition functions such as enzymes, antibodies, and hormones. Three major categories
Physical sensors use physical effects such as piezoelectric effects, magnetostrictive phenomena, ionization, polarization, thermoelectricity, optoelectronics, and magnetoelectric effects. Small changes in the measured signal will be converted into electrical signals.
Chemical sensors include those that are causally related to chemical adsorption, electrochemical reactions, etc. Small changes in the measured signal volume will also be converted into electrical signals.
Chemical sensors include those that are causally related to chemical adsorption, electrochemical reactions, etc. Small changes in the measured signal volume will also be converted into electrical signals.
Biological sensors, based on molecular recognition functions such as enzymes, antibodies, and hormones, some sensors can not be divided into physical categories, can not be divided into chemical categories.
According to its use, the sensor's classification can be divided into:
Pressure Sensitive and Force Sensors, Position Sensors, Level Sensors, Energy Sensors, Speed ​​Sensors, Thermal Sensors, Acceleration Sensors, Ray Radiation Sensors, Vibration Sensors, Sensitive Sensors,
Magnetic sensors, force sensors, vacuum sensors, object sensors, etc.
The sensor can be divided into:
Analog sensor - converts the measured non-electrical quantity into an analog electrical signal.
Digital sensors - convert the non-electrical quantities that are measured into digital output signals (both direct and indirect).
Frequency sensor - The output of the signal to be measured is converted into a frequency signal or a short period signal (including direct or indirect conversion).
Switch Sensor - When a measured signal reaches a certain threshold, the sensor outputs a set low or high signal accordingly.
2 signal processing instruments that are secondary instruments
The second instrument on the weak current is the control room instrument often said. There are many ways to classify instruments in the control room: 1. According to the signal classification: Pneumatic unit combination meter; electric unit combination meter 2. Classified by structure: Base-type instrumentation; Unitized-type instrumentation; Assembled instrumentation 3. Classified by function: display instrument; control instrument; auxiliary instrument 4. According to the installation location: mounted table; rack mounted table Pressure Sensitive and Force Sensors, Position Sensors, Level Sensors, Energy Sensors, Speed ​​Sensors, Thermal Sensors, Acceleration Sensors, Ray Radiation Sensors, Vibration Sensors, Sensitive Sensors,
Magnetic sensors, force sensors, vacuum sensors, object sensors, etc.
The sensor can be divided into:
Analog sensor - converts the measured non-electrical quantity into an analog electrical signal.
Digital sensors - convert the non-electrical quantities that are measured into digital output signals (both direct and indirect).
Frequency sensor - The output of the signal to be measured is converted into a frequency signal or a short period signal (including direct or indirect conversion).
Switch Sensor - When a measured signal reaches a certain threshold, the sensor outputs a set low or high signal accordingly.
2 signal processing instruments that are secondary instruments
3 execution operation class
Such as actuators, valves, inverters, various drive devices, etc.