• The Registering Hygrometer
    The Registering Hygrometer
  • WordNet 3.6
    • n hygrometer measuring instrument for measuring the relative humidity of the atmosphere
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Webster's Revised Unabridged Dictionary
    • n Hygrometer (Physics) An instrument for measuring the degree of moisture of the atmosphere.
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Century Dictionary and Cyclopedia
    • n hygrometer An instrument for measuring the amount of the moisture of the atmosphere, or more accurately for determining the hygrometric state or relative humidity, which is the ratio between the actual amount of water-vapor present in the air and that required in order to saturate it completely. A common form is the Daniell hygrometer, which consists of a bent glass tube terminating in two bulbs, one covered with muslin, the other of black glass and containing ether and a thermometer. Ether being dropped on the muslin of the upper bulb, the vapor within is condensed, and the consequent evaporation of the ether from the other bulb cools the air about it, and finally to such a degree that moisture is deposited upon its black surface. The dropping is now suspended, and the temperature is taken from the inclosed thermometer; the mean between this temperature and that observed when the moisture disappears is the dew-point. The hygrometric state is the ratio between the pressure of water-vapor corresponding respectively to the dew-point and to the temperature of the air at the time as given by the thermometer on the stand. This form is called a dew-point or condensing hygrometer. Instead of a black glass bulb, a silver vessel is sometimes used, as in Regnault's hygrometer. In the chemical hygrometer a known volume of air is passed over some hygroscopic substance, as calcium chlorid, contained in a drying-tube. This absorbs the aqueous vapor, and by its increase in weight gives the means of calculating the amount present in the unit of volume. The wet-bulb thermometer, or psychrometer (see psychrometer), also gives a simple method of obtaining the hygrometric state, by means of appropriately constructed tables.
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Chambers's Twentieth Century Dictionary
    • n Hygrometer hī-grom′et-ėr an instrument for measuring the moisture in the atmosphere, or its relative humidity
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Webster's Revised Unabridged Dictionary
Gr. wet, moist + -meter,: cf. F. hygromètre,
Chambers's Twentieth Century Dictionary
Gr. hygros, wet, metron, a measure.


In literature:

It was difficult to obtain a deposit of dew on the hygrometer, and the working of the aspirator became troublesome.
"The Dominion of the Air" by J. M. Bacon
It crawls forward in all weathers, like Richard Edgeworth's hygrometer.
"Medical Essays" by Oliver Wendell Holmes, Sr.
In the instrument-screen we had a thermograph, hygrometer, and thermometers.
"The South Pole, Volumes 1 and 2" by Roald Amundsen
It was necessary, therefore, constantly to attend and frequently clean the thermographs, hygrometers and the wireless plant.
"The Home of the Blizzard" by Douglas Mawson
At length it grew to such a pitch, that the tube of the hygrometer containing the water was exhausted in a couple of nights.
"The Bushman" by Edward Wilson Landor
Oh for a big, double-barrelled hygrometer, To measure this moisture that rolls from my brow!
"Punchinello, Vol. 1, No. 14, July 2, 1870" by Various
Thus the hygrometer is worthy to be studied on a hunting morning.
"A Cotswold Village" by J. Arthur Gibbs
The Hygrometer, invented by Mr. Daniell, gives the dew-point by inspection.
"Atlantic Monthly Vol. 6, No. 33, July, 1860" by Various
During the approach of the periodic changes of wind and weather, and then the hygrometer, also, should find a place in the journal.
"Discoveries in Australia, Volume 1." by J Lort Stokes
It was of an hygrometer, which, like the common ones, was to give the actual moisture of the air.
"Memoir, Correspondence, And Miscellanies, From The Papers Of Thomas Jefferson" by Thomas Jefferson

In news:

Most hygrometers, digital and analog alike, are calibrated to a specific degree of variation, which is denoted somewhere on the device itself or on the box in which it comes.
Get out your Hygrometer , it's time for sports.
GE has released the Protimeter MMS2, a 4-in-1 moisture measuring instrument which can measure moisture below a surface as well as act as a hygrometer to measure ambient air humidity.
Elcometer has added the new 309 Delta T hygrometer model to its line of climatic condition measuring equipment.

In science:

Ice crystals were grown in free-fall in air, and the supersaturation was determined by sampling the air in the growth chamber with a hygrometer.
A Critical Look at Ice Crystal Growth Data