Form of switch that closes an electrical contact when a certain set temperature has been reached on its input.
A thermometer which infers temperature from a portion of the thermal radiation emitted by the object being measured.
Resistance Temperature Detectors or RTD’s
Electrical resistors that change resistance as temperature changes. A small voltage is passed through the element and then measured. The resistance of the element reduces the voltage and this voltage drop can be converted into a temperature measurement.
Temperature sensing devices that are similar to RTD’s in that their resistance changes as temperature changes, but use a semiconductor device to change resistance rather than a metallic element.
A circuit is formed when two dissimilar metals are joined at both ends and there is a difference in temperature between the two ends. This difference in temperature creates a small current which is converted into a temperature measurement.
Electronic devices that measure temperature and produce an output signal that is both linear and proportional to the sensed temperature.
Gas Filled Mechanical Thermometer
An inert gas under pressure inside a stem expands in response to a change in temperature, thus causing a deflection of the bourdon tube.
Bi-metal Mechanical Thermometer
Consists of a dual strip of different metals, which expands at as it is heated, used to convert a temperature change into mechanical misplacement.
Digital Bi-Metal Thermometer
Consists of a dual strip of different metals, which expands at as it is heated, used to convert a temperature change into mechanical misplacement which is displayed digitally.
Dual reading pressure and temperature instrument.