Thermometric compositions for measuring and indicating low temperatures and related thermometric devices

摘要

For the measurement and the indication of low temperatures, particularly between 0 DEG C. and -30 DEG C., there is foreseen a thermometric composition of cholesteric substances comprising, besides cholesteryl nonanoate, cholesteryl oleyl carbonate and cholesteryl chloride, cholesteryl acetate in an amount increasing with the increase from 0 DEG C. to -30 DEG C. of the temperature to be measured and indicated. There are also contemplated thermometric indicating devices, particularly suitable for the measuring and indicating of the temperature of freezing cells.