ASTM D7984-16

Standard Test Method for Measurement of Thermal Effusivity of Fabrics Using a Modified Transient Plane Source (MTPS) Instrument

SIGNIFICANCE AND USE
5.1 This test method measures the rate of thermal transport between a heating element and a fabric specimen. Some of the comfort properties of a garment relate to initial thermal sensations (that is, cold or warm feeling upon initial contact), where lower thermal effusivity values indicate sensations of warmth and higher values indicate sensations of coolness. The thermal effusivity of different fabrics and their initial perceived surface temperature are important to assist product developers with fabric selection.  
5.2 The sensor and the test specimen being measured shall be at the same temperature for measurements at standard conditions. This test method may be applied to any fabric with a thermal effusivity in the range of 35 to 1700 Ws1/2/m2·K.  
5.3 Air flow shall be kept at a minimum to ensure temperature fluctuations do not occur during the measurement.
SCOPE
1.1 This test method covers the quantitative measurement of thermal effusivity of woven, knitted, or non-woven fabrics using a guarded modified transient plane source (MTPS) instrument.4 This test method is applicable to a wide range of thicknesses; however, the thickness of the specimen must be greater than the penetration depth of the heat flux during the measurement time.  
1.2 This test method is comparative since specimens of known thermal effusivity are used to calibrate the apparatus at the factory level. Thermal effusivity of the calibration specimens are confirmed through calculations that use established properties of thermal conductivity, density, and specific heat.  
1.3 This test method is intended for measuring fabrics in a dry state at ambient conditions.  
1.4 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.  
1.5 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.

General Information

• Status: Historical
• Publication Date: 14-Feb-2016
• ICS: 59.080.30 - Textile fabrics
• Technical Committee: D13 - Textiles
• Drafting Committee: D13.51 - Conditioning, Chemical and Thermal Properties

Standards Content (Sample)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation:D7984 −16
Standard Test Method for
Measurement of Thermal Effusivity of Fabrics Using a
1
Modified Transient Plane Source (MTPS) Instrument
This standard is issued under the fixed designation D7984; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
INTRODUCTION
This standard provides a test method for measuring the thermal effusivity of fabrics under still air
conditions. Other standards, Test Methods F1868 and D1518, measure the thermal insulation of
materials under steady-state conditions; however, this test method is used to measure transient heat
exchangebetweenafabricspecimenandaheatedsurface.Ithasbeenestablishedthatthereisastrong
positive correlation between the thermal effusivity and the initial perceived coldness between human
2,3
skin and different materials.
1. Scope 1.5 This standard does not purport to address all of the
safety concerns, if any, associated with its use. It is the
1.1 Thistestmethodcoversthequantitativemeasurementof
responsibility of the user of this standard to establish appro-
thermal effusivity of woven, knitted, or non-woven fabrics
priate safety and health practices and determine the applica-
using a guarded modified transient plane source (MTPS)
4 bility of regulatory limitations prior to use.
instrument. This test method is applicable to a wide range of
thicknesses; however, the thickness of the specimen must be
2. Referenced Documents
greater than the penetration depth of the heat flux during the
5
2.1 ASTM Standards:
measurement time.
D123Terminology Relating to Textiles
1.2 This test method is comparative since specimens of
D1518Test Method for Thermal Resistance of Batting
known thermal effusivity are used to calibrate the apparatus at
Systems Using a Hot Plate
the factory level. Thermal effusivity of the calibration speci-
D1776Practice for Conditioning and Testing Textiles
mens are confirmed through calculations that use established
D4920Terminology Relating to Conditioning, Chemical,
properties of thermal conductivity, density, and specific heat.
and Thermal Properties
1.3 This test method is intended for measuring fabrics in a
E691Practice for Conducting an Interlaboratory Study to
dry state at ambient conditions.
Determine the Precision of a Test Method
E177Practice for Use of the Terms Precision and Bias in
1.4 The values stated in SI units are to be regarded as
ASTM Test Methods
standard. No other units of measurement are included in this
F1868Test Method forThermal and Evaporative Resistance
standard.
of Clothing Materials Using a Sweating Hot Plate
1
ThistestmethodisunderthejurisdictionofASTMCommitteeD13onTextiles 3. Terminology
andisthedirectresponsibilityofSubcommitteeD13.51onConditioning,Chemical
3.1 Definitions of Terms Specific to This Standard:
and Thermal Properties.
Current edition approved Feb. 15, 2016. Published March 2016. DOI: 10.1520/ 3.1.1 modified transient plane source (MTPS), n—an appa-
D7984-16.
ratus that has a one sided planar heat source and a guard, or
2
Marin, E., “Teaching Thermal Physics by Touching,” Latin-American Journal
guard ring, mounted perpendicular to the planar heat source,
of Physics Education, Vol 2, No. 1, January 2008, pp. 15-17.
3 that is put in contact with one side of a test specimen, so that
Wongsriruska, S., Howes, P., Conreen, M., Miodownik, M., “The Use of
PhysicalPropertyDatatoPredicttheTouchPerceptionofMaterials,” Materials and
a short duration heat pulse can penetrate into the specimen.
Design, Vol 42, 2012, pp. 238-244.
4
ThesolesourceofsupplyoftheTCiinstrumentknowntothecommitteeatthis
time is C-Therm Technologies, Ltd., C/O RPC, 921 College Hill Rd., Fredericton,
5
NewBrunswick,Canada,E3B6Z9.Ifyouareawareofalternativesuppliers,please For referenced ASTM standards, visit the ASTM website, www.astm.org, or
provide this information toASTM International Headquarters.Your comments will contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
1
receive careful consideration at a meeting of the responsible technical committee, Standards volume information, refer to the standard’s Document Summary page on
which you may attend. the ASTM website.
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D7984−16
3.1.1.1 Discussion—The purpose of the guard (or guard 5. Significance and Use
ring) is to maintain a consistent unidirectional heat flow across
5.1 This test method measures the rate of thermal transport
the test specimen.
between a heating element and a fabric specimen.
...