relative humidity

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Related to relative humidity: absolute humidity, dew point


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.
Miller-Keane Encyclopedia and Dictionary of Medicine, Nursing, and Allied Health, Seventh Edition. © 2003 by Saunders, an imprint of Elsevier, Inc. All rights reserved.

rel·a·tive hu·mid·i·ty

the actual amount of water vapor present in the air or in a gas, divided by the amount necessary for saturation at the same temperature and pressure; expressed as a percentage.
Farlex Partner Medical Dictionary © Farlex 2012

rel·a·tive hu·mid·i·ty

(rel'ă-tiv hyū-mid'i-tē)
The actual amount of water vapor present in the air or in a gas, divided by the amount necessary for saturation at the same temperature and pressure; expressed as a percentage.
Medical Dictionary for the Health Professions and Nursing © Farlex 2012

rel·a·tive hu·mid·i·ty

(rel'ă-tiv hyū-mid'i-tē)
Actual amount of water vapor present in air or gas, divided by amount necessary for saturation at same temperature and pressure; expressed as a percentage.
Medical Dictionary for the Dental Professions © Farlex 2012
References in periodicals archive ?
Therefore, it is usually hard to understand its relationship with temperature and relative humidity while ignoring other biotic and abiotic factors.
Relative humidity and rain affected malaria incidence rates in the following locations: northeastern Thailand: in Mukdahan in 2012, Kalasin in 2013, and Khon Kaen in 2017; eastern Thailand: in Prachin Buri in 2017; western Thailand: in Tak in 2013 and 2014; southern Thailand: in Narathiwat, Pattani, and Yala in 2016; northern Thailand: in Mae Hong Son in 2012, 2013, and 2016; Lamphun in 2014; and Chiang Mai in 2015; and central Thailand: in Kamphaeng Phet in 2013; Phetchabun in 2014; Phitsanulok in 2016; and Bangkok in 2014 and 2016.
Therefore, the relationship between the hydration degree of cementitious material and the relative humidity change inside the material was established.
Correlation analysis showed that (Table 2) minimum temperature gave significant negative correlation coefficients and morning relative humidity showed significant positive correlation coefficients for all the three dates of sowing.
The effect of relative humidity on resistance to abscission, which is a way to estimate the force with which the berries are attached to the rachis, was only affected at 0 days of shelf life (Figure 2C), whose response was represented by a parabola with maximum force at 92% relative humidity.
Internal air temperature and relative humidity values were measured by means of a data logger TESTO 175H1 equipped with air temperature and humidity probes.
While shut down their room conditions would heat up in summer thus lowering their relative humidity, and cool down to set back settings on winter nights.
The humidity indication range for paper indicators is from 10% to 70% relative humidity although this must be specified at an ambient temperature and tolerance range.
Hence, we designed a bench scale triboelectrostatic separator unit and investigated several factors such as air velocity, mixture ratio, relative humidity on the charge polarity and charge density of PVC/XLPE.
The packaging was exposed to various environments for at least 19 days: conditioned air at 39 C, 90% relative humidity; 39 C, 50% humidity; and 23 C, 50% humidity.

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