ASTM F1720-17(2023)
(Test Method)Standard Test Method for Measuring Thermal Insulation of Sleeping Bags Using a Heated Manikin
Standard Test Method for Measuring Thermal Insulation of Sleeping Bags Using a Heated Manikin
SIGNIFICANCE AND USE
5.1 This test method can be used to quantify and compare the insulation provided by sleeping bags or sleeping bag systems. It can be used for material and design evaluations.
5.2 The measurement of the insulation provided by clothing (see Test Method F1291, ISO 15831) and sleeping bags (ISO 23537) is complex and dependent on the apparatus and techniques used. It is not practical in a test method of this scope to establish details sufficient to cover all contingencies. It is feasible that departures from the instructions in this test method will lead to significantly different test results. Technical knowledge concerning the theory of heat transfer, temperature and air motion measurement, and testing practices is needed to evaluate which departures from the instructions given in this test method are significant. Standardization of the method reduces, but does not eliminate, the need for such technical knowledge. Any departures need to be reported with the results.
SCOPE
1.1 This test method covers determination of the insulation value of a sleeping bag or sleeping bag system. It measures the resistance to dry heat transfer from a constant skin temperature manikin to a relatively cold environment. This is a static test that generates reproducible results, but the manikin cannot simulate real life sleeping conditions relating to some human and environmental factors, examples of which are listed in the introduction.
1.2 The insulation values obtained apply only to the sleeping bag or sleeping bag system, as tested, and for the specified thermal and environmental conditions of each test, particularly with respect to air movement past the manikin.
1.3 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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.
1.4 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.
General Information
Relations
Standards Content (Sample)
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: F1720 − 17 (Reapproved 2023) An American National Standard
Standard Test Method for
Measuring Thermal Insulation of Sleeping Bags Using a
Heated Manikin
This standard is issued under the fixed designation F1720; 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
Sleeping bags are used by people in outdoor environments to insulate them from the cold (that is,
reduce their body heat loss to the environment). Sleeping bags often are used with ground pads and
clothing inside tents that provide additional protection from the environment. The amount of
insulation needed in a sleeping bag depends upon the air temperature and a number of other
environmental factors (for example, wind speed, radiant temperature, moisture in the air), human
factors (for example, a person’s metabolic heat production that is affected by gender, age, fitness level,
body type, size, position, and movement), and physical factors (for example, amount of body coverage
and the quality of the insulating materials). The insulation value, expressed in clo units, can be used
to characterize sleeping bags and sleeping bag systems. Insulation values for sleeping bag systems can
be used in body heat loss models to predict the temperature ratings for comfort.
1. Scope mendations issued by the World Trade Organization Technical
Barriers to Trade (TBT) Committee.
1.1 This test method covers determination of the insulation
value of a sleeping bag or sleeping bag system. It measures the
2. Referenced Documents
resistance to dry heat transfer from a constant skin temperature
2.1 ASTM Standards:
manikin to a relatively cold environment. This is a static test
F1291 Test Method for Measuring the Thermal Insulation of
that generates reproducible results, but the manikin cannot
Clothing Using a Heated Manikin
simulate real life sleeping conditions relating to some human
2.2 ISO Standards:
and environmental factors, examples of which are listed in the
ISO 15831 2004 Clothing—Physiological Effects—
introduction.
Measurement of Thermal Insulation by Means of a Ther-
1.2 The insulation values obtained apply only to the sleep-
mal Manikin
ing bag or sleeping bag system, as tested, and for the specified
ISO 23537-1 2016 Requirements for Sleeping Bags – Part 1:
thermal and environmental conditions of each test, particularly
Thermal and Dimensional Requirements
with respect to air movement past the manikin.
1.3 This standard does not purport to address all of the 3. Terminology
safety concerns, if any, associated with its use. It is the
3.1 Definitions:
responsibility of the user of this standard to establish appro-
3.1.1 auxiliary products, n—items used with a sleeping bag
priate safety, health, and environmental practices and deter-
to create a sleeping bag system such as clothing, camp pillow,
mine the applicability of regulatory limitations prior to use.
ground pad, and bivy sack.
1.4 This international standard was developed in accor-
3.1.2 clo, n—unit of thermal resistance (insulation) equal to
dance with internationally recognized principles on standard-
0.155°C·m /W.
ization established in the Decision on Principles for the
3.1.2.1 Discussion—The value of 1 clo was selected as
Development of International Standards, Guides and Recom-
roughly the insulation value of a heavy men’s business suit,
1 2
This test method is under the jurisdiction of ASTM Committee F08 on Sports For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Equipment, Playing Surfaces, and Facilities and is the direct responsibility of contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
Subcommittee F08.22 on Camping Softgoods. Standards volume information, refer to the standard’s Document Summary page on
Current edition approved Nov. 1, 2023. Published December 2023. Originally the ASTM website.
approved in 1996. Last previous edition approved in 2017 as F1720 – 17. DOI: Available from American National Standards Institute (ANSI), 25 W. 43rd St.,
10.1520/F1720-17R23. 4th Floor, New York, NY 10036.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
F1720 − 17 (2023)
which should keep a resting man (producing heat at the rate of 6. Apparatus
58 W/m ) comfortable in an environment at 21 °C, air move- 4
6.1 Manikin —Use a supine manikin that is formed in the
ment 0.1 m/s.
shape and size of an adult male or female and is capable of
being heated to a constant, average surface temperature.
3.1.3 dry heat loss, n—heat transferred from the body
6.1.1 Size and Shape—Construct the manikin to simulate
surface to a cooler environment by means of conduction,
the body of a human being, that is, with a head, chest/back,
convection, and radiation.
abdomen/buttocks, arms, hands, legs, and feet. Total surface
2 2
3.1.4 manikin, n—a life-size model of the human body with
area shall be 1.8 m 6 0.3 m , and height shall be 170 cm 6
a surface temperature similar to that of a human being.
10 cm. Any departures from this description need to be
reported.
3.1.5 sleeping bag, n—a structure made of down, synthetic
6.1.2 Surface Temperature—Construct the manikin so as to
fiberfill, shell fabrics, or other materials, or a combination
maintain a constant temperature distribution over the entire
thereof, that is designed for people to use for thermal protec-
nude body surface with no local hot or cold spots. Ensure that
tion when sleeping (for example, outdoors, tent, cabin).
the mean skin temperature of the manikin is either 34 °C or
3.1.6 sleeping bag system, n—sleeping bag used with aux-
35 °C. Do not allow local deviations from the mean skin
iliary products such as clothing, ground pad, and bivy sack.
temperature to exceed 60.3 °C. Evaluate temperature unifor-
mity of the nude manikin at least once annually using an
3.1.7 thermal insulation, n—resistance to dry heat transfer
infrared thermal imaging system, a surface (contact) tempera-
by way of conduction, convection, and radiation.
ture probe, or equivalent method. This procedure also needs to
3.1.8 total insulation (I ), n—the resistance to dry heat loss
T be repeated after repairs or alterations are completed that could
from the manikin that includes the resistance provided by the
affect temperature uniformity, for example, replacing a heating
sleeping bag, auxiliary products (if used) and the surface air
element.
layer around the manikin.
6.2 Power-Measuring Instruments—Measure the power to
3.1.8.1 Discussion—Total insulation values (I ) are mea-
T
the manikin so as to give an accurate average over the period
sured directly with a manikin. They can be used to compare
of a test. If time proportioning or phase proportioning is used
different sleeping bags, as long as each test is conducted using
for power control, then devices that are capable of averaging
the same experimental procedures and test conditions.
over the control cycle are required. Integrating devices (watt-
hour meters) are preferred over instantaneous devices (watt
4. Summary of Test Method
meters). Overall accuracy of the power monitoring equipment
must be within 62 % of the reading for the average power for
4.1 A heated manikin is placed inside a sleeping bag or
the test period. Since there are a variety of devices and
sleeping bag system in a cold environmental chamber.
techniques used for power measurement, this standard does not
4.2 The power needed to maintain a constant body tempera-
provide specific calibration procedures. Develop and document
ture is measured. an appropriate power calibration procedure.
6.3 Equipment for Measuring the Manikin’s Skin
4.3 The total thermal insulation of the sleeping bag or
Temperature—The mean skin temperature shall be measured
sleeping bag system (including the resistance of the external air
with point sensors or distributed temperature sensors.
layer) is calculated based on the skin temperature and surface
6.3.1 Point Sensors—Point sensors shall be thermocouples,
area of the manikin, the air temperature, and the power level.
resistance temperature devices (RTDs), thermistors, or equiva-
lent sensors. Ensure that they are no more than 2 mm thick and
5. Significance and Use
are well bonded, both mechanically and thermally, to the
5.1 This test method can be used to quantify and compare
manikin’s surface. Bond lead wires to the surface or pass
the insulation provided by sleeping bags or sleeping bag
through the interior of the manikin, or both. Area-weight each
systems. It can be used for material and design evaluations.
sensor temperature when calculating the mean skin tempera-
ture for the body. If point sensors are used, a minimum of 11
5.2 The measurement of the insulation provided by clothing
point sensors are required. At least one sensor shall be placed
(see Test Method F1291, ISO 15831) and sleeping bags (ISO
on the head, chest, back, arms, legs, hands, and feet. These
23537) is complex and dependent on the apparatus and
sensors must be placed in the same position for each test, and
techniques used. It is not practical in a test method of this scope
the placement of the sensors shall be given in the report.
to establish details sufficient to cover all contingencies. It is
6.3.2 Distributed Sensors—If distributed sensors are used
feasible that departures from the instructions in this test method
(for example, resistance wire), then the sensors must be
will lead to significantly different test results. Technical knowl-
distributed over the surface so that all areas are equally
edge concerning the theory of heat transfer, temperature and air
weighted. If several such sensors are used to measure the
motion measurement, and testing practices is needed to evalu-
ate which departures from the instructions given in this test
method are significant. Standardization of the method reduces,
Information on laboratories with heated manikins can be obtained from the
but does not eliminate, the need for such technical knowledge.
Institute for Environmental Research, Kansas State University, Manhattan, KS
Any departures need to be reported with the results. 66506.
F1720 − 17 (2023)
temperature of different parts of the body, then their respective 8. Preparation of Sleeping Bags
temperatures need to be area-weighted when calculating the
8.1 The sleeping bag shall be the appropriate size for the
mean surface (skin) temperature. Distributed sensors must be
manikin with respect to its width and length. A bag that fits
less than 1 mm in diameter and firmly attached to the manikin
tightly and causes compression in the head, feet, or hip areas
surface at all points.
may have a lower insulation value than one that does not cause
6.4 Controlled Environmental Chamber—Place the manikin compression.
in a chamber at least 3 m by 2 m by 2.6 m in dimension that
8.2 Bags shall be tested prior to laundering or dry cleaning
can provide uniform conditions, both spatially and temporally.
because it is feasible that the procedures will affect the results.
6.4.1 Spatial Variations—Do not exceed the following: air
8.3 If auxiliary products are used, select the correct size for
temperature 61.0 °C, relative humidity 65 %, and air velocity
the manikin.
650 % of the mean value. In addition, the mean radiant
temperature shall not be more than 1.0 °C different from the
9. Test Procedure
mean air temperature. Verify the spatial uniformity at least
annually or after any significant modifications are made to the
9.1 Environmental Test Conditions—The standard condi-
chamber. Verify spatial uniformity by recording values for the
tions for all tests are given as follows.
conditions stated above at 0.6 m (the midline elevation of the
9.1.1 Air Temperature—The air temperature shall be at least
manikin on the cot) and 1.1 m above the floor at the location
25 °C lower than the manikin’s mean surface temperature
occupied by the manikin. Use sensing devices specified below
during a test (that is, 10 °C or lower, see 9.2).
when measuring the environmental conditions.
9.1.2 Air Velocity—Use a fan to produce an air velocity of
6.4.2 Temporal Variations—Do not exceed the following:
0.3 m ⁄s 6 0.1 m ⁄s. If horizontal air flow is used, position the
air temperature 60.5 °C, mean radiant temperature 60.5 °C,
bag and manikin so that the direction of the air flow is from the
relative humidity 65 %, and air velocity 620 % of the mean
head to the feet.
value for data averaged over 5 min (see 6.4.5).
9.1.3 Relative Humidity—Maintain the relative humidity
6.4.3 Relative Humidity Measuring Equipment—Any hu-
between 30 % and 80 % for all tests.
midity sensing device with an accuracy of 65 % relative
humidity and a repeatability of 63 % is acceptable (for
9.2 Mean Skin Temperature of Manikin—The manikin’s
example, wet bulb/dry bulb, dew point hygrometer). Only one mean surface temperature shall be either 34 °C 6 0.3 °C or
location needs to be monitored during a test to ensure that the
35 °C 6 0.3 °C for all tests. The mean surface temperature
temporal uniformity requirements are met. shall not be allowed to drift more than 60.1 °C during a 30 min
test.
6.4.4 Air Temperature Sensors—Shielded air temperature
sensors shall be used. Any sensor with an overall accuracy of
9.3 Options—Select one of the following procedures.
60.15 °C is acceptable (for example, RTD, thermocouple,
9.3.1 Option 1: Sleeping Bag Test—Place the sleeping bag
thermistor). The sensor shall have a time constant not exceed-
on the nude manikin on a cot in the environmental chamber and
ing 1 min. The sensor(s) shall be located at the midline
measure its insulation.
elevation of the manikin (0.6 m from the floor), at least 0.4 m
9.3.1.1 This approach is used when comparing the design,
from the manikin. It is acceptable to use a single sensor, but
construction, and filling materials of different bags. Small
multiple sensors are preferred. If a single sensor is used, it shall
differences in insulation will be easier to detect when the bag
be located midway between the head and the feet. If multiple
is tested alone.
sensors are used, they shall be spaced equally from the head to
9.3.1.2 Bags are also tested alone for quality control
the feet and their readings averaged.
purposes, including production lot testing for the military.
6.4.5 Air Velocity Indicator—Use an om
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