ligLiquid in Glass* thermometers are among the oldest types of temperature sensors in continuous use for many purposes, not the least of which is the familiar clinical, fever thermometers.

An information web page on About Temperature & Moisture Sensors  that has organized web links pointing to sites that describe Liquid in Glass* thermometers, how they work and more, including the recent changes in standards and usage of Mercury-filled devices in most progressive, advanced countries.


* Some low-cost,  modern thermometers are made of other materials.