Bimetallic thermometers and their mode of operation

Bimetallic thermometers and their mode of operation

What is a Bimetal Thermometer? How do bimetallic thermometers work? Where are bimetallic thermometers used?

Bimetallic thermometers and how they work

The bimetallic thermometer is an instrument used to measure temperature through the contraction and expansion of two different metallic alloys with high and low coefficient of expansion.

Bimetallic thermometers are made up of a tube inside which a bimetallic helical spiral is placed. Said spiral is welded at one end to the lower part of the tube and at the other to a transmission rod, in turn connected to an indicator needle.

Operation of bimetallic thermometers

Metal alloys, those with high and low coefficient of expansion, when exposed to a certain temperature, transmit a rotating movement to an indicator needle, that is, temperature variations cause the Bimetal Thermometer to undergo deformation, this is transmitted to the needle indicator

Bimetallic thermometers use the difference in the coefficient of thermal expansion of dissimilar metals to determine what the temperature change is. This is provided by a mechanical movement, that is, by turning a hand on a graduated scale.

Actually, what measures the temperature in bimetallic thermometers is a fast-response bimetallic helix. Since the bimetallic thermometer is manufactured from two cold-welded metal strips with various thermal coefficients of expansion, they twist as a function of temperature and the rotary motion is transferred with low friction to the indicating needle.

Uses and applications of bimetallic thermometers

The use of bimetallic thermometers is very extensive since they are designed to withstand the most rigorous working conditions, being in contact with aggressive process fluids or adverse environments. Thanks to the fact that they are ideal for measuring temperature directly, therefore, the industries that use them the most are:

  • The food
  • Conservation
  • Pharmaceutical
  • Chemistry
  • Petro chemistry
  • Paper bin

Bimetallic Thermometer Suppliers

Here’s a look at The Control Store, a provider of Bimetal Thermometer and Piston Snubber:

The Control Store is a company dedicated to providing instrumentation equipment, whose main function is to measure, control and record the variables of a process: Pressure (absolute and differential), flow, level (liquid or solid), temperature, and humidity, among others; in order to optimize the resources used in this.

The Control Store’s instrumentation teams also include some Petroleum Research, Development and Testing teams, among others.