dew point

dew point:

see dewdew,
thin film of water that has condensed on the surface of objects near the ground. Dew forms when radiational cooling of these objects during the nighttime hours also cools the shallow layer of overlying air in contact with them, causing the condensation of some water vapor.
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Dew Point

the temperature at which air becomes saturated by water vapor when cooled at a given moisture content and a constant pressure. The condensation of water vapor begins when the dew point is reached in the air or on objects in contact with the air.

The dew point is one of the major characteristics of humidity and can be calculated from the temperature and humidity of the air or determined directly with a condensation hygrometer. If the relative humidity is less than 100 percent, the dew point is always less than the actual air temperature. The dew point decreases with decreasing relative humidity.

At saturation, that is, at a relative humidity of 100 percent, the actual temperature coincides with the dew point. Thus, at a temperature of 15°C, the relative humidities of 100, 80, 60, and 40 percent correspond to the dew points of 15.0°, 11.6°, 7.3°, and 1.5°C, respectively.

dew point

[′dü ‚pȯint] (chemistry) The temperature and pressure at which a gas begins to condense to a liquid. (meteorology) The temperature at which air becomes saturated when cooled without addition of moisture or change of pressure; any further cooling causes condensation. Also known as dew-point temperature.

dew point

If the temperature is +30°C and there is 15 gm of water vapor per kg of dry air and the air is cooled to +20°C, saturation will occur. +20°C is the Dew point. Similarly, Dew point is +33°C if air with 5 gm of water vapor per kg is cooled till it becomes saturated.The temperature to which a given parcel of air must be cooled at constant pressure and constant-water-vapor content for saturation to occur. It is the temperature at which the saturation vapor pressure of the parcel is equal to the actual vapor pressure of the contained water vapor. Any further cooling usually results in the formation of dew or frost. Also called the dew-point temperature. When this temperature is below 0°C, it is sometimes called the frost point.

dew point

point

[point] 1. a small area or spot; the sharp end of an object.2. to approach the surface, like the pus of an abscess, at a definite spot or place.3. a tapered, pointed endodontic instrument used for exploring the depth of the root canal in therapy" >root canal therapy; called also root canal point.point A a radiographic, cephalometric landmark, determined on the lateral head film; it is the most retruded part of the curved bony outline from the anterior nasal spine to the crest of the maxillary alveolar process.absorbent point in root canal therapy, a cone of variable width and taper, usually made of paper or a paper product, used to dry or maintain a liquid disinfectant in the canal. Called also paper point.point B a radiographic, cephalometric landmark, determined on the lateral head film; it is the most posterior midline point in the concavity between the infradentale and pogonion.boiling point the temperature at which a liquid will boil; at sea level the boiling point of water is 100°C (212°F).cardinal p's 1. the points on the different refracting media of the eye that determine the direction of the entering or emerging light rays.2. four points within the pelvic inlet— the two sacroiliac articulations and the two iliopectineal eminences.craniometric p's the established points of reference for measurement of the skull.dew point the temperature at which moisture in the atmosphere is deposited as dew.far point the most remote point at which an object is clearly seen when the eye is at rest.point of fixation 1. the point or object on which one's sight is fixed and through which the axis opticus passes.2. the point on the retina, usually the fovea, on which are focused the rays coming from an object directly regarded.freezing point the temperature at which a liquid begins to freeze, for water, 0°C (32°F); it is often used interchangeably with point" >melting point, but should be used for substances being cooled while melting point is reserved for substances being heated.gutta-percha point gutta-percha cone.ice point the true melting point of ice, being the temperature of equilibrium between ice and air-saturated water under one atmosphere pressure.isoelectric point (pI) the pH of a solution in which molecules of a specific substance, such as a protein, have equal numbers of positively and negatively charged groups and therefore do not migrate in an electric field.J point on an electrocardiogram, the junction between the end of the QRS segment and the beginning of the ST segment.jugal point the point at the angle formed by the masseteric and maxillary edges of the zygomatic bone; called also jugale.lacrimal point a small aperture on a slight elevation at the medial end of the eyelid margin, through which tears from the lacrimal lake enter the lacrimal canaliculi. See also lacrimal apparatus.point of maximal impulse the point on the chest where the impulse of the left ventricle is sometimes felt or seen most strongly, normally in the fifth costal interspace inside the mammillary line.McBurney point a point of special tenderness in appendicitis, about 4 to 5 cm from the right anterior iliac spine on a line between the spine and the navel; it corresponds to the normal position of the appendix.

McBurney's point is located midway between the anterior iliac crest and the umbilicus in the right lower quadrant. From Ignatavicius and Workman, 2002.melting point (mp) the minimum temperature at which a solid begins to liquefy; see also point" >freezing point.near point the nearest point of clear vision, the absolute near point being that for either eye alone with accommodation relaxed, and the relative near point being that for the two eyes together with employment of accommodation.nodal p's two points on the axis of an optical system situated so that a ray falling on one will produce a parallel ray emerging through the other.paper point absorbent point.pressure point 1. a point of extreme sensitivity to pressure.2. one of various locations on the body at which digital pressure may be applied for the control of hemorrhage.

Locations of pressure points. Shaded areas show the regions in which hemorrhage may be controlled by pressure at the points indicated.root canal point point (def. 3).silver point in therapy" >root canal therapy, a tapered and elongated silver plug that is cemented into the canal as a filling. Called also silver cone.trigger point a spot on the body at which pressure or other stimulus gives rise to specific sensations or symptoms.triple point the temperature and pressure at which the solid, liquid, and gas phases of a substance are in equilibrium.

dew point

the temperature at and below which moisture will condense for a specific humidity.

dew point

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dew′ point`

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dew point:

Dew Point

dew point

dew point

dew point

point

dew point

dew point

Words related to dew point

noun the temperature at which the water vapor in the air becomes saturated and condensation begins

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