Bimetallic strip

Bimetallic Strips
 
Bonding two metals with dissimilar thermal expansion coefficients can produce useful devices for detecting and measuring temperature changes. A typical pair is brass and steel with typical expansion coefficients of 19 and 13 parts per million per degree Celsius respectively.

The examples shown are straight strips, but bimetallic strips are made in coils to increase their sensitivity for use in thermostats. One of the many uses for bimetallic strips is in electrical breakers where excessive current through the strip heats it and bends it to trip the switch to interrupt the current.

Jalur dwilogam

Melekatkan dua jalur logam yang punyai kadar pengembangan yang berlainan berguna untuk membuat alat untuk mengesan perubahan suhu. Sejenis jalur dwilogam daripada besi dan loyang masing-masing dengan kadar pengembangan  13 dan  19 bahagian perjuta per darjah Celsius.