ASTM F1868-98

NOTICE: This standard has either been superceded and replaced by a new version or discontinued.
Contact ASTM International (www.astm.org) for the latest information.
Designation: F 1868 – 98
Standard Test Method for
Thermal and Evaporative Resistance of Clothing Materials
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Using a Sweating Hot Plate
This standard is issued under the fixed designation F 1868; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (e) indicates an editorial change since the last revision or reapproval.
INTRODUCTION
Clothing is often made of materials that impede the flow of heat and moisture from the skin to the
environment. Consequently, people may suffer from heat stress or cold stress when wearing clothing
in different environmental conditions. Therefore, it is important to quantify the thermal resistance and
evaporative resistance of clothing materials and to consider these properties when selecting materials
for different clothing applications.
1. Scope F 1291 Test Method for Measuring the Thermal Insulation
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of Clothing Using a Heated Manikin
1.1 This test method covers the measurement of the thermal
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F 1494 Terminology Relating to Protective Clothing
resistance and the evaporative resistance, under steady-state
2.2 Other Standards:
conditions, of fabrics, films, coatings, foams, and leathers,
ISO 11092 Textiles–Physiological Effects–Measurement of
including multi-layer assemblies, for use in clothing systems.
Thermal and Water-Vapour Resistance Under Steady-
1.2 The range of this measurement technique for thermal
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2
State Conditions (Sweating Guarded-Hotplate Test)
resistance is from 0.002 to 0.2 K·m /W and for evaporative
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NFPA 1971 Protective Clothing for Structural Fire Fight-
resistance is from 0.01 to 1.0 kPa·m /W.
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ing
1.3 The values in SI units shall be regarded as standard.
NFPA 1977 Protective Clothing and Equipment for Wild-
1.4 This standard does not purport to address all of the
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land Fire Fighting
safety concerns, if any, associated with its use. It is the
responsibility of the user of this standard to consult and
3. Terminology
establish appropriate safety and health practices and deter-
3.1 Definitions:
mine the applicability of regulatory limitations prior to use.
3.1.1 clo, n-, n—unit of thermal resistance defined as the
2. Referenced Documents insulation required to keep a resting man (producing heat at the
2
rate of 58 W/m ) comfortable in an environment at 21°C, air
2.1 ASTM Standards:
movement 0.1 m/s, or roughly the insulation value of typical
C 177 Test Method for Steady-State Heat Flux Measure-
indoor clothing.
ments and Thermal Transmission Properties by Means of
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3.1.1.1 Discussion—Numerically the clo is equal to 0.155
the Guarded-Hot-Plate Apparatus
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3
K·m /W.
D 1518 Thermal Transmittance of Textile Materials
3.1.2 evaporative heat transmittance, n—time rate of undi-
E 177 Practice for Use of the Terms Precision and Bias in
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rectional evaporative heat transfer per unit area, in the steady
ASTM Test Methods
state, between parallel planes, per unit difference of water
E 641 Practice for Conducting an Interlaboratory Study to
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vapor pressure of the planes.
Determine the Precision of a Test Method
3.1.2.1 Discussion—Evaporative heat transmittance is ex-
pressed as watts per square metre of test specimen per
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This test method is under the jurisdiction of ASTM Committee F-23 on
Protective Clothing and is the direct responsibility of Subcommittee F23.60 on
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Human Factors. Annual Book of ASTM Standards, Vol 11.03.
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Current edition approved June 10, 1998. Published August 1998. Available from American National Standards Institute, 11 West 42nd St, New
2
Annual Book of ASTM Standards, Vol 04.06. York, NY 10036.
3 7
Annual Book of ASTM Standards, Vol 07.01. Available from National Fire Protection Assoc., 1 Batterymarch Park, Quincy,
4
Annual Book of ASTM Standards, Vol 14.02. MA 02269.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
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NOTICE: This standard has either been superceded and replaced by a new version or discontinued.
Contact ASTM International (www.astm.org) for the latest information.
F1868–98
kilopascal of vapor pressure difference between the test plate that the boundary layers of the bare plate and the boundary
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and the environment (W/m ·kPa). The evaporative heat trans- layers of the fabric test specimen are equal.
mittance may consist of both diffusive and convective compo- R = total thermal resistance of the test specimen and the air
ct
nents. layer.
3.1.7 total clo, n—clo plus the thermal resistance from the
3.1.3 evaporative resistance, n—reciprocal of evaporative
air boundary layer, (clo ).
heat transmittance expressed in kilopascals, square metre of
t
3.1.8 total heat l
...