1.2 SENSOR TYPES
• A list of physical properties, and sensors to measure them is given below,
- 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.