The earliest surviving bimetallic strip was made by the 18th-century clockmaker John Harrison, who is generally credited with its invention in 1759. A bimetallic strip is used to convert a temperature change into mechanical displacement.
The bimetal dial pocket thermometer used by sanitarians and chefs was introduced in the 1940s. Within a decade, the bimetal dial thermometer replaced the liquid-filled, armor-clad thermometers that were previously used.
This 1-in. dial pocket thermometer with a 2-in. bimetal coil was manufactured by Weston Instruments, Co. from Newark, New Jersey. This thermometer was issued to New Jersey sanitarians from the 1950s to the late 1960s.
