Hydrometric /(?)/

Hy·dro·met·ric

Hydrometric

a.
  1. Of or pertaining to an hydrometer, or to the determination of the specific gravity of fluids.
  2. Of or pertaining to measurement of the velocity, discharge, etc., of running water.
  3. Made by means of an hydrometer; as, hydrometric observations.

Phrases & Compounds
Hydrometric pendulum
a species of hydrometer consisting of a hollow ball of ivory or metal suspended by a treated from the center of a graduated quadrant, and held in a stream to measure the velocity of the water by the inclination given to the thread; a kind of current gauge.