What is the operating temperature of glycerine?

“BOSHART” Liquid filled Gauges are filled with 100% (99.7% min.) glycerine, which starts to become viscous at +17°C. As the temperature decreases, the more viscous glycerine becomes, causing the pointer to move slower to its correct position, it can take several minutes.

At-5°C these gauges no longer operate. For operating temperatures less than -5°C, glycerine is mixed: 2 parts glycerine with 1 part water (66.7%), which actually lowers the freezing point of the solution allowing the gauge to be used in temperatures as low as -46°c. This 66.7% glycerine mix is available for such applications.