4. Classification of sensors

Sensors can be classified into various groups according to the factors such as measurand, application fields, conversion principle, energy domain of the measurand and thermodynamic considerations. These general classifications of sensors are well described in the references [2, 3].

Detail classification of sensors in view of their applications in manufacturing is as follows.

1. Displacement, position and proximity sensors
   • Potentiometer
   • Strain-gauged element
   • Capacitive element
   • Differential transformers
   • Eddy current proximity sensors
   • Inductive proximity switch
   • Optical encoders
   • Pneumatic sensors
   • Proximity switches (magnetic)
   • Hall effect sensors
2. Velocity and motion
   • Incremental encoder
   • Tachogenerator
   • Pyroelectric sensors
3. Force
• Strain gauge load cell
4. Fluid pressure
• Diaphragm pressure gauge
• Capsules, bellows, pressure tubes
• Piezoelectric sensors
• Tactile sensor
5. Liquid flow
• Orifice plate
• Turbine meter
6. Liquid level
• Floats
• Differential pressure
7. Temperature
• Bimetallic strips
• Resistance temperature detectors
• Thermistors
• Thermo-diodes and transistors
• Thermocouples
• Light sensors
• Photo diodes
• Photo resistors
• Photo transistor 

 

Principle of operation of these transducers and their applications in manufacturing are presented in the next lectures.