1.2 SENSOR TYPES

 

• A list of physical properties, and sensors to measure them is given below,

 

 

 

 

 

 

 

 

 

• Common transducers,

- Ammeter - meter to indicate electrical current

- Bourdon tube - widely used industrial gage to measure pressure and vacuum

- Chromatographic instruments - laboratory-type instruments used to analyze chemical compounds and gases.

- Inductance-coil pulse generator - transducer used to measure rotational speed. Output is pulse train.

- Linear-Variable-Differential transformer (LVDT) electromechanical transducer used to measure angular or linear displacement. Output is Voltage

- Manometer - liquid column gage used widely in industry to measure pressure.

- Ohmmeter - meter to indicate electrical resistance

- Optical Pyrometer - device to measure temperature of an object at high temperatures by sensing the brightness of an objects surface.

- Orifice Plate - widely used flowmeter to indicate fluid flow rates

- Photometric Transducers - a class of transducers used to sense light, including phototubes, photodiodes, phototransistors, and photoconductors.

- Piezoelectric Accelerometer - Transducer used to measure vibration. Output is emf.

- Pitot Tube - Laboratory device used to measure flow.

- Positive displacement Flowmeter - Variety of transducers used to measure flow. Typical output is pulse train.

- Potentiometer - instrument used to measure voltage

- Pressure Transducers - A class of transducers used to measure pressure. Typical output is voltage. Operation of the transducer can be based on strain gages or other devices.

- Radiation pyrometer - device to measure temperature by sensing the thermal radiation emitted from the object.

- Strain Gage - Widely used to indicate torque, force, pressure, and other variables. Output is change in resistance due to strain, which can be converted into voltage.

- Thermistor - Also called a resistance thermometer; an instrument used to measure temperature. Operation is based on change in resistance as a function of temperature.

- Thermocouple - widely used temperature transducer based on the Seebeck effect, in which a junction of two dissimilar metals emits emf related to temperature.

- Turbine Flowmeter - transducer to measure flow rate. Output is pulse train.

- Venturi Tube - device used to measure flow rates.