1、Designation: E 41 92 (Reapproved 2004)Standard Terminology Relating ToConditioning1This standard is issued under the fixed designation E 41; the number immediately following the designation indicates the year of originaladoption or, in the case of revision, the year of last revision. A number in par
2、entheses indicates the year of last reapproval. A superscriptepsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 These definitions pertain to the conditioning of materialsfor test purposes. Unless otherwise specified, they are intendedto apply to all cases whe
3、re combinations of atmosphericinfluences are an essential part of the testing of materials.1.2 It is the intent of this standard to include those condi-tioning terms in wide use in ASTM for which standarddefinitions appear desirable.2. Referenced Documents2.1 ASTM Standards:E 171 Specification for S
4、tandard Atmospheres for Condi-tioning and Testing MaterialsE 337 Test Method for Measuring Humidity with a Psy-chrometer (the Measurement of Wet- and Dry-Bulb Tem-peratures)3. Terminology3.1 Definitions:air conditioningthe simultaneous control of all, or at leastthe first three, of those factors aff
5、ecting both the physical andchemical conditions of the atmosphere within any structure.These factors include temperature, humidity, motion, distri-bution, dust, bacteria, odor, and toxic gases.air, dryair containing no water vapor.air, saturateda mixture of dry air and water vapor in whichthe latter
6、 is at its maximum concentration for the prevailingtemperature and pressure.atmospheric pressurethe pressure due to the weight of theatmosphere. It is the pressure indicated by a barometer thatregisters actual atmospheric pressure which is not correctedto sea level equivalence. Standard atmospheric
7、pressure is apressure of 76 cm Hg (101325 Pa) having a density of13.5951 g/cm3, under standard gravity of 980.665 cm/s2.atmosphere, standardair maintained at a specified tempera-ture, relative humidity, and standard atmospheric pressure.E 171condition, standardthe condition reached by a specimenwhen
8、 it is in temperature and moisture equilibrium with astandard atmosphere.conditioningthe exposure of a material to the influence of aprescribed atmosphere for a stipulated period of time or untila stipulated relation is reached between material and atmo-sphere.dehumidifyto reduce, by any process, th
9、e quantity of watervapor within a given space.dew pointthe temperature to which water vapor must bereduced to obtain saturation vapor pressure, that is, 100 %relative humidity.NOTE 1As air is cooled, the amount of water vapor that it can holddecreases. If air is cooled sufficiently, the actual water
10、 vapor pressurebecomes equal to the saturation water-vapor pressure, and any furthercooling beyond this point will normally result in the condensation ofmoisture.humidifyto increase, by any process, the quantity of watervapor within a given space.humidistata regulatory device, activated by changes i
11、nhumidity, used for the automatic control of relative humidity.humiditythe condition of the atmosphere in respect to watervapor. (See also humidity, absolute; humidity, relative.)humidity, absolutethe weight of water vapor present in aunit volume of air, for example, grains per cubic foot, orgrams p
12、er cubic metre.NOTE 2The amount of water vapor is also reported in terms of weightper unit weight of dry air, for example, grains per pound of dry air. Thisvalue differs from values calculated on a volume basis and should not bereferred to as absolute humidity. It is designated as humidity ratio,spe
13、cific humidity, or moisture content, which also see.humidity ratioin a mixture of water vapor and air, the massof water vapor per unit mass of dry air.humidity, relativethe ratio of the actual pressure of existingwater vapor to the maximum possible (saturation) pressureof water vapor in the atmosphe
14、re at the same temperature,expressed as a percentage.humidity, specificin a mixture of water vapor and air, themass of water vapor per unit mass of moist air.moisture contentthe moisture present in a material, asdetermined by definite prescribed methods, expressed as apercentage of the weight of the
15、 sample on either of thefollowing bases:1These definitions are under the jurisdiction of ASTM Committee G3 onDurability of Nonmetallic Materials and are the direct responsibility of Subcom-mittee G03.92 on Terminology.Current edition approved May 15, 1992. Published September 1992. Originallypublish
16、ed as E 41 42 T. Last previous edition E 41 86.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.(1) Original weight (Note 3).(2) Moisture-free weight (Note 4).NOTE 3This is variously referred to as moisture content or moisture“as is”
17、or “as received.”NOTE 4This is also referred to as moisture regain (frequently con-tracted to “regain”) or moisture content on the “oven-dry,” “moisture-free,” or “dry” basis.moisture equilibriumthe condition reached by a samplewhen the net difference between the amount of moistureabsorbed and the a
18、mount desorbed, as shown by a change inweight, shows no trend and becomes insignificant.moisture regainthe moisture in a material determined underprescribed conditions and expressed as a percentage of theweight of the moisture-free specimen.NOTE 5Moisture regain may result from either absorption or
19、desorp-tion, and differs from moisture content only in the basis used forcalculation.preconditioningany preliminary exposure of a material tothe influence of specified atmospheric conditions for thepurpose of favorably approaching equilibrium with a pre-scribed atmosphere.pressure, saturationthe pre
20、ssure, for a pure substance atany given temperature, at which vapor and liquid, or vaporand solid, coexist in stable equilibrium.pressure, vaporthe pressure exerted by a vapor.NOTE 6If a vapor is kept in confinement over its source so that thevapor can accumulate, the temperature being held constant
21、, the vaporpressure approaches a fixed limit called the maximum, or saturated, vaporpressure, dependent only on the temperature and the liquid.pressure, water vaporthe component of atmospheric pres-sure caused by the presence of water vapor, usually ex-pressed in millimetres, inches of mercury, or p
22、ascals.room temperaturea temperature in the range of 20 to 30C(68 to 85F).NOTE 7The term “room temperature” is usually applied to anatmosphere of unspecified relative humidity.saturationthe condition of coexistence in stable equilibriumof a vapor and a liquid or a vapor and solid phase of the samesu
23、bstance at the same temperature.saturation, degree ofthe ratio of the weight of water vaporassociated with a pound of dry air to the weight of watervapor associated with a pound of dry air saturated at thesame temperature.standard laboratory atmospherean atmosphere, the tem-perature and relative hum
24、idity of which is specified, withtolerances on each. E 171temperaturethe thermal state of matter as measured on adefinite scale.temperature, dew pointsee dew point.temperature, dry-bulbthe temperature of the air as indi-cated by an accurate thermometer, corrected for radiation ifsignificant.temperat
25、ure, wet-bulbwet bulb temperature (without quali-fication) is the temperature indicated by a wet-bulb psy-chrometer constructed and used according to specifications.E 337vaporthe gaseous form of substances that are normally inthe solid or liquid state, and that can be changed to thesestates either b
26、y increasing the pressure or decreasing thetemperature.4. Significance and Use4.1 This terminology is not intended to supersede similardefinitions in certain other existing documents, but is intendedto provide a listing of terms that are in current widespreadusage, and their context in relation to c
27、onditioning of testmaterials.5. Keywords5.1 atmosphere; conditioning; humidity; pressure;temperatureThis standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years andif not revised, either reapproved or withdrawn. Your comments are invit
28、ed either for revision of this standard or for additional standardsand should be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of theresponsible technical committee, which you may attend. If you feel that your comments have not received a
29、 fair hearing you shouldmake your views known to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org).E 41 92 (2004)2
