1.Non-toxic spirit filled glass tube 2.magnifying lens 3.hangs, stands or permanently mounts

About Bimetal thermometer

A bi-metallic strip is used to convert a temperature change into mechanical displacement.

The strip consists of two strips of different metals which expand at different rates as they are heated,usually steel and copper . or in some cases brass instead of copper. The strips are joined together throughout their length either riveting, brazing or welding. The different expansions force

the flat strip to bend one way if heated, and in the opposite direction if cooled below its normal temperature. The metal with the higher coefficient of thermal expansion is on the outer side of the curve when the strip is heated and on the inner side when cooled.Oil filled,could use for equipment.

Digital thermometer