Psy̆-chrōm'e-ter, a.

(sī-krōm'e-ter), a. [Fr. psychromètre, from Gr. ψυχρός, cold, and μέτρον, measure.] An instrument for measuring the tension of the aqueous vapor in the atmosphere, consisting of two delicate thermometers, the bulb of one of which is kept constantly moistened, the dew-point, or tension of aqueous vapor, being deduced from the difference of the readings of the two scales; a wet and dry bulb hygrometer.