Fahrenheit's hydrometer
Fahrenheit's hydrometer
[′far·ən‚hīts hī′dräm·əd·ər] (engineering)
A type of hydrometer which carries a pan at its upper end in which weights are placed; the relative density of a liquid is measured by determining the weights necessary to sink the instrument to a fixed mark, first in water and then in the liquid being studied.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.