Bimetallic Strip Thermometer

Bimetallic strips are used in thermostats for measuring and controlling temperature. The strip is connected to a switch and as the temperature changes the strip flexes and opens or closes a contact. They are also used in ovens for measuring temperature.

Where are bimetallic strip thermometers used?

Bimetallic thermometers are used in residential devices like air conditioners, ovens, and industrial devices like heaters, hot wires, refineries, etc. They are a simple, durable, and cost-efficient way of temperature measurement.

Which thermometer has bimetallic strips?

Thermometers. A direct indicating dial thermometer, common in household devices (such as a patio thermometer or a meat thermometer), uses a bimetallic strip wrapped into a coil in its most common design.

How does a strip thermometer work?

A liquid crystal thermometer, temperature strip or plastic strip thermometer is a type of thermometer that contains heat-sensitive (thermochromic) liquid crystals in a plastic strip that change colour to indicate different temperatures.

Why bimetallic strip is used?

Bimetallic strip is used to convert a temperature change into a mechanical displacement. It consists of two strips of different metals which expands at different rates as they are heated.

What is the use of bimetallic thermometer?

Bimetallic thermometers are widely used in industry. Their typical range is from 40–800 (°F). They are often used for two-position temperature control in residential and industrial thermostats.

What happens when bimetallic strip is heated?

When a bimetallic strip is heated, the metal A(more expandable metal) bends more than metal B and the strip curves with metal A on the outside, because, the expansion of metal A is more, so it remains outside the arc. And if the strip is cooled, metal B will be on the outside.

What are the advantages and disadvantages of bimetallic thermometer?

advantages	disadvantages
Bimetallic thermometer *
cheap	requires frequent calibration to maintain accuracy
durable	fairly slow response
can be used for thermograph

What is a bimetallic thermometer made of?

Constructions of Bimetallic Thermometer. The bimetallic strip is constructed by bonding together the two thin strips of different metals. The metals are joined together at one end with the help of the welding. The bonding is kept in such a way that there is no relative motion between the two metals.

What is a bimetallic strip explain in detail?

noun. a strip consisting of two metals of different coefficients of expansion welded together so that it buckles on heating: used in thermostats, etc.

In what principle does a bimetallic strip operate?

Definition: A bimetallic strip works on the principle of thermal expansion, which is defined as the change in volume of metal with the change in temperature.

Why do bimetallic strips bend?

A bimetallic strip consists of a strip of two different metals welded together. When we heat it, different metals expand by different amounts. It bends due to thermal expansion. Thermal expansion is the tendency of matter to change in shape, area, and volume in response to a change in temperature.

How accurate are temperature strips?

There aren't many studies on the use of strip thermometers but most recognize the accuracy of detecting fever at around 35 to 50 percent.

What happens when the strip is heated?

The strip of bimetal comprises two metals with different coefficients of thermal expansion. The metal with a higher coefficient will expand at first when heated. The expansion results in bending. Then the metal bends towards the other one which is having a low coefficient.

What are the 4 types of thermometer?

There are different types, but not all thermometers are right for your child.

• Digital thermometers.
• Ear (or tympanic) thermometers. ...
• Infared thermometers. ...
• Strip-type thermometers. ...
• Mercury thermometers.

Which are important properties for selection of bimetallic strip material?

Properties of bimetal The behaviour of bimetals is predictable and repeatable. The components used for bimetals are selected for their temperature characteristics as well as their thermal conductivity, stability, strength, workability, and electrical properties.

Why does bimetallic strip expand?

At normal room temperature, the two strips have the same length. However, since brass expands (or contracts) more than iron when its temperature is raised (or cooled), the bimetallic strip will bend one way or another depending on the temperature being above or below room temperature.

Does a refrigerator use a bimetallic strip?

Answer. When the temperature inside the refrigerator rises, the bimetallic strip bends to switch on the compressor which starts the cooling cycle.

What happens when a bimetallic strip is cooled below room temperature?

When this bimetallic strip is heated, the brass expands more than the steel and the strip curves with the brass on the outside. If the strip is cooled, it curves with the steel on the outside.

What are the disadvantages of bimetallic strip work?

Main disadvantages are they are not very accurate and they are not suitable for measuring lower temperature as the metals and metallic alloys show nearly same expansion or contraction in lower range of temperature.