JIS B 7549:2017

This Standard specifies the liquid filled system thermometers consisting of a temperature sensitive cylinder, a conduit tube and a pressure conversion part, all of which are connected as a unit and filled with a liquid. The indicator in a round case has a single pointer and scales concentrically marked on the dial. The pressure change is caused by the volumetric change of the liquid, and in the system according to the temperature change at the temperature sensitive part is converted to a mechanical displacement of the pointer to indicate the temperature. The thermometers are used in the temperature range of minus 50 degrees Celsius to plus 300 degrees Celsius.