Register thermometer

a thermometer that registers the maximum and minimum of temperature occurring in the interval of time between two consecutive settings of the instrument. A common form contains a bit of steel wire to be pushed before the column and left at the point of maximum temperature, or a slide of enamel, which is drawn back by the liquid, and left within it at the point of minimum temperature.

See also: Thermometer

Webster's Revised Unabridged Dictionary, published 1913 by G. & C. Merriam Co.