A vertical temperature profile recorder, utilizing a thermistor as the temperature sensing element, has been developed for use on lakes, bays, or other enclosed or semi-enclosed bodies of water where temperature profiles in the upper 30 m are desired. Tests of the instrument indicate that it is rugged and durable, giving easily readable records accurate to ± 0.1 ° C....
Anderson, Ernest R., and Arthur T. Burke. 1951. "Notes on the development of a thermistor temperature profile recorder (TPR)." Journal of Marine Research 10, (2). https://elischolar.library.yale.edu/journal_of_marine_research/743