cryoscope

noun

1. (physical)A device used to measure the freezing point of a liquid (or the melting point of a solid).

   “Since this work was undertaken, Raoult has kindly informed me that he has repeated his work with cane-sugar, using an improved cryoscope, constructed so as to prevent direct radiation from the freezing-mixture to the bulb of the thermometer.”

   “It has been considered preferable to adhere to the apparent freezing point as determined by a standard cryoscope, rather than to confuse matters by attempting to apply corrections, which may or may not be themselves correct.”