Why The Accuracy Of Bimetallic Thermometers

Why The Accuracy Of Bimetallic Thermometers


Almost everyone is familiar with thermometers, especially thermometers used to measure body temperature. Homes and businesses also have thermometers to measure the temperature of food and determine if the kamado needs to be turned on or off. Traditional thermometers are bulb thermometers that contain some particular liquid such as mercury and rely on the principle that the liquid changes its volume in relation to temperature.

Another type of thermometer, called a bimetal thermometer, relies on the principle that different metals expand at different speeds when exposed to heat. Combining two different metals into a bimetal strip makes it more sensitive to small changes in temperature. Most bimetal strips use a combination of high thermal expansion alloys such as steel and stainless steel with low thermal expansion allies such as Invar.

Two way bimetal strip

Spiral Strips – Bimetal strips are wrapped in a spiral attached to a dial that indicates temperature.

Cantilever Strips – Bimetal strips are joined by cantilever. Deflection is used to indicate temperature.

Typically, the strip is wrapped around a thermometer, which expands and decreases as the temperature changes, and the hands move directly over the dial to indicate the temperature. Bimetal thermometers do not require power, so they are cost-effective and simply read the temperature readings on the dial. For industrial applications, the bimetal thermometer has a large, easy -to -read dial and is made of durable stainless construction. A moistened silicon-filled bimetal thermometer provides accurate and reliable temperature readings in high-vibration environments such as manufacturing plants. In addition to the bimetal thermometers used in refrigerators, ovens and furnaces, there are infiltration bimetal thermometers for food processing and production.

Range and accuracy of bimetal thermometer

Bimetallic thermometers are generally considered to be very reliable and accurate, especially for home thermostats. The small pocket thermometers used to test air conditioning systems and cooking temperatures have a diameter of approximately 1 inch, but have a temperature range of 0 to 220 degrees Fahrenheit, marked in 2 degrees Fahrenheit. increase. Larger units with 2, 3, and 5 inch dial surfaces are typically accurate up to 1% of the unit span. Ranges up to 1000 degrees Fahrenheit are available, but those within 500 degrees Fahrenheit are more common.

The important role of the bimetal thermometer in the food industry

The most common thermometers used in the food industry are bimetal stem thermometers that can measure temperatures from 0oF to 220oF (-18oC to 104oC). Among its many important features are adjustable calibration nuts for accuracy, easy to read numbered temperature marks, and to mark the edges of the detection area with an accuracy of up to +/- 2 oF or 1 degree. Celsius. There are dimples. Bimetal thermometers control time and temperature and play a major role in food safety and quality. Bimetal thermometers are the most important tool for protecting food.


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