Liquid-in-glass (LIG) thermometers are a remarkably long-lived technology. œe Ÿrst sealed LIG thermometers were based on the thermal expansion of wine spirit and developed in 1641 by the then Duke of Tuscany [1,2]. For the next 300 years, the technology gradually improved so that a bewildering variety of LIG thermometers are now available to suit almost every application. œey cover temperature ranges from −190 °C to 600 °C, and some achieve accuracies approaching 0.001 °C. œe distinctive form, self-contained nature, and apparent simplicity of the LIG thermometer have made it the archetypical thermometer for many generations of technical sta¥ and the general public.