ASTM F2371-16(2024)

This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation: F2371 − 16 (Reapproved 2024)
Standard Test Method for
Measuring the Heat Removal Rate of Personal Cooling
Systems Using a Sweating Heated Manikin
This standard is issued under the fixed designation F2371; 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 (´) indicates an editorial change since the last revision or reapproval.
INTRODUCTION
Personal Cooling Systems (PCS) are used when wearers could be exposed to conditions that render
the body’s thermoregulatory system inadequate to maintain body core temperature within a safe range.
The use of PCS can reduce the possibility of heat stress related physiological disorders and can also
provide increased comfort, which in turn could also result in higher productivity. Cooling needs vary
greatly depending on the level of activity, the external temperature and humidity, as well as the
personal protective equipment worn. The PCS should be selected that is best suited for the specific
application. Sweating heated manikins provide a convenient tool to assess the effectiveness of PCS as
they can provide objective and repeatable results. These instruments can be used to quantify, in a
reproducible manner, the cooling rate and cooling duration provided by the PCS while eliminating the
variables associated with human physiology. Sweating heated manikins can be used for direct
comparisons of PCS.
1. Scope from the manikin than they would be from a human, particu-
larly in environments with higher levels of humidity.
1.1 This test method uses a sweating manikin in an envi-
ronmental chamber to measure the heat removal rate and 1.3 The values stated in SI units are to be regarded as
cooling duration provided by a personal cooling garment worn standard. No other units of measurement are included in this
with a base ensemble. standard.
1.1.1 The use of a sweating heated manikin is essential
1.4 This standard does not purport to address all of the
because of the potentially large amount of heat dissipation
safety concerns, if any, associated with its use. It is the
from the body associated with evaporative cooling.
responsibility of the user of this standard to establish appro-
priate safety, health, and environmental practices and deter-
1.2 The experimental values obtained for the cooling rates
mine the applicability of regulatory limitations prior to use.
and cooling duration apply only to the particular PCS and
1.5 This international standard was developed in accor-
additional garments worn during the test and for the environ-
dance with internationally recognized principles on standard-
mental conditions used.
ization established in the Decision on Principles for the
1.2.1 It is feasible that this test method will yield unrealis-
Development of International Standards, Guides and Recom-
tically high cooling rates for ambient air circulation systems
mendations issued by the World Trade Organization Technical
since the manikin’s surface stays continuously saturated during
Barriers to Trade (TBT) Committee.
the test and the relative humidity in the chamber is relatively
low; consequently the convective and evaporative heat loss
2. Referenced Documents
rates from the body to the environment are probably higher
2.1 ASTM Standards:
F1291 Test Method for Measuring the Thermal Insulation of
Clothing Using a Heated Manikin
This test method is under the jurisdiction of ASTM Committee F23 on Personal
F1494 Terminology Relating to Protective Clothing
Protective Clothing and Equipment and is the direct responsibility of Subcommittee
F23.60 on Human Factors.
F2370 Test Method for Measuring the Evaporative Resis-
Current edition approved Feb. 1, 2024. Published February 2024. Originally
tance of Clothing Using a Sweating Manikin
approved in 2005. Last previous edition approved in 2016 as F2371 – 16. DOI:
10.1520/F2371-16R24.
2 3
The present standard does not attempt to determine the thermal insulation and For referenced ASTM standards, visit the ASTM website, www.astm.org, or
evaporative resistance of garments worn with the PCS, or these same properties for contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
the PCSs themselves. Test Methods F1291 and F2370 are available for these Standards volume information, refer to the standard’s Document Summary page on
measurements. the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
F2371 − 16 (2024)
3. Terminology body surface, with no local hot or cold spots. The mean surface
(skin) temperature of the manikin shall be 35 °C. Local
3.1 For definitions of terms related to protective clothing
deviations from the mean surface temperature shall not exceed
used in this test method, refer to Terminology F1494.
60.5 °C. Temperature uniformity of the nude manikin shall be
3.2 Definitions:
evaluated at least once annually using an infrared thermal
3.2.1 personal cooling systems (PCS)—garment technolo-
imaging system or equivalent method. Repeat this procedure
gies that are designed to be worn with protective clothing in
after repairs or alterations are completed that could affect
warm/hot environments to remove heat from the body and
temperature uniformity, for example, replacement of a heating
prevent heat stress; types include ambient air systems which
element.
circulate air between the body surface and clothing, phase
5.2 Power-Measuring Instruments—Record the time history
change materials which are worn close to the body and absorb
heat, and refrigeration systems and ice bath systems that of the power input to the manikin over the entire test period.
circulate chilled water in tubes in a vest worn next to the body Overall accuracy of the power monitoring equipment must be
(that is, a liquid cooling garment). within 62 % of the reading for the average power for the test
period. Since there are a variety of devices and techniques used
4. Significance and Use
for power measurement, no specified calibration procedures
4.1 This test method can be used to quantify and compare
shall be given. However, an appropriate power calibration
the cooling provided by different personal cooling systems
procedure is to be developed and documented.
(PCS) worn with a common base ensemble. Any base en-
5.3 Equipment for Measuring the Manikin’s Surface (Skin)
semble can be selected based on the intended end use of the
Temperature—Measure the mean skin temperature with point
PCS.
sensors or distributed temperature sensors.
4.1.1 The test method is intended to allow garments based
on various cooling technologies to be evaluated fairly and 5.3.1 Point Sensors—The following are acceptable point
sensors: thermocouples, resistance temperature devices
objectively, by taking into account both dry and evaporative
heat transfer. (RTDs), thermistors, or equivalent sensors. They shall be no
more than 2.0 mm thick and shall be well bonded, both
4.2 The measurements of heat removal rates and duration of
mechanically and thermally, to the manikin’s surface. Lead
cooling provided by the PCS depend on the apparatus, the base
wires shall be bonded to the surface or pass through the interior
ensemble, and the techniques used.
of the manikin, or both. The sensors shall be distributed so that
4.2.1 Departures from the instructions in this test method
each one represents the same surface area or are area-weighted
will potentially lead to significantly different test results.
when calculating the mean skin temperature for the body. If
4.2.2 Technical knowledge concerning the theory of heat
point senors are used, a minimum of 15 point sensors are
transfer, temperature, air motion measurement, humidity,
required. At least one sensor shall be placed on the head, chest,
evaporative cooling, and testing practices is needed to evaluate
back, abdomen, buttocks, and both the right and left upper arm,
which departures from the instructions given in this test
lower arm, hand, thigh, calf, and foot. These sensors must be
method are significant. Report any departures with the results.
placed in the same position for each test and the placement of
5. Apparatus
the sensors shall be given in the report.
5.1 Manikin—A standing sweating manikin shall be used
5.3.2 Distributed Sensors—If distributed sensors are used
that is formed in the shape and size of an adult male or female
(for example, resistance wire), then the sensors must be
and heated to a constant average surface temperature.
distributed over the surface so that all areas are equally
5.1.1 Size and Shape—The manikin shall be constructed to
weighted. If several such sensors are used to measure the
simulate the body of a human being; that is, it shall consist of
temperature of different parts of the body, then their respective
a head, chest/back, abdomen, buttocks, arms, hands (preferably
temperatures need to be area-weighted when calculating the
with fingers extended to allow gloves to be worn), legs, and
mean surface (skin) temperature. Distributed sensors shall be
feet. Total surface area shall be 1.8 6 0.3 m , and height shall
less than 1 mm in diameter and firmly attached to the manikin
be 170 6 10 cm. The manikin’s dimensions shall correspond to
surface at all points.
those required for standard sizes of garments because devia-
5.4 Controlled Environmental Chamber—The manikin shall
tions in fit will significantly affect the results.
be placed in a chamber at least 2 by 2 by 2 m in dimension that
5.1.2 Sweat Generation—The manikin must have the ability
can provide uniform conditions, both spatially and temporally.
to evaporate water from its surface. The sweating system can
5.4.1 Spatial Variations—Spatial variations shall not exceed
be a water-fed capillary body suit worn over a thermal manikin.
the following: air temperature 61.0 °C, relative humidity
Sweating can also be simulated by supplying water to and
maintaining it at the inner surface of a waterproof but moisture- 65 %, and air velocity 650 % of the mean value. In addition,
the mean radiant temperature shall not be more than 1.0 °C
permeable fabric skin.
5.1.2.1 Sweating Surface Area—The entire surface of the different from the mean air temperature. The spatial uniformity
shall be verified at least annually or after any significant
manikin shall be heated and sweating including the head, chest,
back, abdomen, buttocks, arms, hands, legs, and feet. modifications are made to the chamber. Spatial uniformity shall
be verified by recording values for the conditions stated above
5.1.3 Surface Temperature—The manikin shall be con-
structed so as to maintain a uniform temperature over the nude at heights of 0.1, 0.6, 1.1, 1.4, and 1.7 m above the floor at the
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