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absolute humidity
absolute humidityn. The amount of water vapor present in a unit volume of air, usually expressed in grams per cubic meter.absolute humidity n (General Physics) the humidity of the atmosphere, usually expressed as the number of grams of water contained in 1 cubic metre of air. Compare relative humidity ab·so·lute humidity (ăb′sə-lo͞ot′) The amount of water vapor present in a unit volume of air, usually expressed in kilograms per cubic meter. Compare relative humidity.absolute humidity
absolute humidity[′ab·sə‚lüt hyü′mid·ə·dē] (physics) The ratio of the mass of water vapor in a sample of air to the volume of the sample. absolute humidityThe mass of water vapor per unit volume of air.absolute humidityThe mass of water vapor present per unit volume of space (i.e., the density of water vapor, usually expressed in gm/m3). It is the actual amount of water, by weight, in water vapor in a given volume of space. Also known as vapor concentration.absolute humidity
humidity [hu-mid´ĭ-te] the degree of moisture in the air.absolute humidity the actual amount of vapor in the atmosphere, expressed in milligrams per liter.relative humidity the percentage of moisture in the air as compared to the amount necessary to cause saturation, which is taken as 100.humidity therapy the therapeutic use of water to prevent or correct a moisture deficit in the respiratory tract. Under normal conditions the respiratory tract is kept moist by humidifying mechanisms that allow for evaporation of water from the respiratory mucosa. If these mechanisms fail to work, are bypassed (such as with an endotracheal tube), or are inadequate to overcome the drying and irritating effects of therapeutic gases and mucosal crusting, some form of humidification must be provided.
The principal reasons for employing humidity therapy are: (1) to prevent drying and irritation of the respiratory mucosa, (2) to facilitate ventilation and diffusion of oxygen and other therapeutic gases being administered, and (3) to aid in the removal of thick and viscous secretions that obstruct the air passages. Another important use of water aerosol therapy is to aid in obtaining an induced sputum specimen.
Humidity therapy may be delivered in a variety of ways. Humidifiers and vaporizers increase the water content of an environment and are limited to the treatment of upper respiratory disorders because they produce particles that are too large to penetrate deeply into the lungs. Nebulizers generate clouds or mists of particles that are extremely small and thus capable of penetrating more deeply into the bronchioles and small structures of the lower respiratory tract. Examples of these include jet instruments and ultrasonic nebulizers.ab·so·lute hu·mid·i·tythe mass of water vapor actually present per unit volume of gas or air.ab·so·lute hu·mid·i·ty (ab'sŏ-lūt' hyū-mid'i-tē) The mass of water vapor actually present per unit volume of gas or air. AcronymsSeealdehydeThesaurusSeehumidity |