What's the difference between gravimeter and hydrometer?

Gravimeter

Definition:

Example Sentences:

(1) Therefore concentration of these two fractions has to be systematically measured.--The paper presents a dust gravimeter--new in its structural composition--suitable for measuring concentration of the two fractions simultaneously and separately.
(2) Using a gravimeter, body sway studied in 26 chronic schizophrenic patients, 10 schizoaffective disorder patients and 21 normal subjects.

Definition:

(n.) An instrument for determining the specific gravities of liquids, and thence the strength spirituous liquors, saline solutions, etc.
(n.) An instrument, variously constructed, used for measuring the velocity or discharge of water, as in rivers, from reservoirs, etc., and called by various specific names according to its construction or use, as tachometer, rheometer, hydrometer, pendulum, etc.; a current gauge.

Example Sentences:

(1) The following noninvasive measuring methods were used for evaluation of the skin before and after exposure to irritants: measurement of transepidermal water loss by an evaporimeter, measurement of electrical conductance by a hydrometer, measurement of skin blood flow by laser Doppler flowmetry, measurement of skin colour by a colorimeter and measurement of skin thickness by ultrasound A-scan.
(2) The concentration of solids (or water) in urine can be measured by weighing, hydrometer, refractometry, surface tension, osmolality, a reagent strip, or oscillations of a capillary tube.
(3) the Skicon-100 and Corneometer CM 420 hydrometers and the Servo Med EPI evaporimeter.
(4) In an attempt to analyze the "texture match" of grafted skin, functional and morphological aspects of the stratum corneum were studied using the Skin Surface Hydrometer (IBS Inc.) and the scanning electron microscope.
(5) In conclusion, both hydrometers were deemed relevant and valid for assessment of skin moisture.
(6) Specific gravity of the colostrum was measured using a hydrometer in increments of 5 degrees C from 0 to 40 degrees C. Specific gravity explained 76% of the variation in colostral total IgG at a colostrum temperature of 20 degrees C. The regression model was improved only slightly with the addition of protein, fat, and total solids.