ASTM E337 - 02(2007)

    Standard Test Method for Measuring Humidity with a Psychrometer (the Measurement of Wet- and Dry-Bulb Temperatures)

    Active Standard ASTM E337 | Developed by Subcommittee: D22.11

    Book of Standards Volume: 11.07


      Format Pages Price  
    PDF 24 $62.00   ADD TO CART
    Hardcopy (shipping and handling) 24 $62.00   ADD TO CART


    1. Scope

    1.1 General

    1.1.1 This test method covers the determination of the humidity of atmospheric air by means of wet- and dry-bulb temperature readings.

    1.1.2 This test method is applicable for meteorological measurements at the earth's surface, for the purpose of the testing of materials, and for the determination of the relative humidity of most standard atmospheres and test atmospheres.

    1.1.3 This test method is also applicable when the temperature of the wet bulb only is required. In this case, the instrument comprises a wet-bulb thermometer only.

    1.1.4 Relative humidity (RH) does not denote a unit. Uncertainties in the relative humidity are expressed in the form RH rh %, which means that the relative humidity is expected to lie in the range (RH rh) % to (RH + rh ) %, where RH is the observed relative humidity. All uncertainties are at the 95 % confidence level.

    1.2 Method A- Psychrometer Ventilated by Aspiration:

    1.2.1 This method incorporates the psychrometer ventilated by aspiration. The aspirated psychrometer is more accurate than the sling (whirling) psychrometer (see Method B), and it offers advantages in regard to the space which it requires, the possibility of using alternative types of thermometers (for example, electrical), easier shielding of thermometer bulbs from extraneous radiation, accidental breakage, and convenience.

    1.2.2 This method is applicable within the ambient temperature range 5 to 80C, wet-bulb temperatures not lower than 1C, and restricted to ambient pressures not differing from standard atmospheric pressure by more than 30 %.

    1.3 Method B- Psychrometer Ventilated by Whirling (Sling Psychrometer):

    1.3.1 This method incorporates the psychrometer ventilated by whirling (sling psychrometer).

    1.3.2 This method is applicable within the ambient temperature range 5 to 50C, wet-bulb temperatures not lower than 1C and restricted to ambient pressures not differing from standard atmospheric pressure by more than 30 %.

    1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. (For more specific safety precautionary statements, see 8.1 and 15.1 .)<


    2. Referenced Documents (purchase separately) The documents listed below are referenced within the subject standard but are not provided as part of the standard.

    ASTM Standards

    D861 Practice for Use of the Tex System to Designate Linear Density of Fibers, Yarn Intermediates, and Yarns

    D1193 Specification for Reagent Water

    D1356 Terminology Relating to Sampling and Analysis of Atmospheres

    D1357 Practice for Planning the Sampling of the Ambient Atmosphere

    D3631 Test Methods for Measuring Surface Atmospheric Pressure

    D4023 Terminology Relating to Humidity Measurements

    D4230 Test Method of Measuring Humidity with Cooled-Surface Condensation (Dew-Point) Hygrometer

    E1 Specification for ASTM Liquid-in-Glass Thermometers


    ICS Code

    ICS Number Code 07.060 (Geology. Meteorology. Hydrology)

    UNSPSC Code

    UNSPSC Code 81151700(Geology); 81151500(Meteorology)


    Referencing This Standard

    DOI: 10.1520/E0337-02R07

    ASTM International is a member of CrossRef.

    Citation Format

    ASTM E337-02(2007), Standard Test Method for Measuring Humidity with a Psychrometer (the Measurement of Wet- and Dry-Bulb Temperatures), ASTM International, West Conshohocken, PA, 2007, www.astm.org

    Back to Top