ASTM F1939-15(2020)
(Test Method)Standard Test Method for Radiant Heat Resistance of Flame Resistant Clothing Materials with Continuous Heating
Standard Test Method for Radiant Heat Resistance of Flame Resistant Clothing Materials with Continuous Heating
SIGNIFICANCE AND USE
5.1 This test method is intended for the determination of the radiant heat resistance value of a material, a combination of materials, or a comparison of different materials used in flame-resistant clothing for workers exposed to radiant thermal hazards.
5.2 This test method evaluates a material's heat transfer properties when exposed to a continuous and constant radiant heat source. Air movement at the face of the specimen and around the calorimeter can affect the measured heat transferred due to forced convective heat losses. Minimizing the air movement around the specimen and test apparatus will aid in the repeatability of the results.
5.3 This test method maintains the specimen in a static, vertical position and does not involve movement, except that resulting from the exposure.
5.4 This test method specifies two standard sets of exposure conditions: 21 kW/m2 (0.5 cal/cm2s) and 84 kW/m2 (2.0 cal/cm2s). Either can be used.
5.4.1 If a different set of exposure conditions is used, it is likely that different results will be obtained.
5.4.2 The optional use of other conditions representative of the expected hazard, in addition to the standard set of exposure conditions, is permitted. However, the exposure conditions used must be reported with the results along with a determination of the exposure energy level stability.
5.5 This test method does not predict skin burn injury from the standardized radiant heat exposure.
Note 4: See Appendix X4 for additional information regarding this test method and predicted skin burn injury.
SCOPE
1.1 This test method rates the non-steady state thermal resistance or insulating characteristics of flame resistant clothing materials subjected to a continuous, standardized radiant heat exposure.
1.1.1 This test method is not applicable to clothing materials that are not flame resistant.
Note 1: The determination of a clothing material's flame resistance shall be made prior to testing and done in accordance with the applicable performance standard, specification standard, or both, for the clothing material's end use.
1.1.2 This test method does not predict skin burn injury from the standardized radiant heat exposure, as it does not account for the thermal energy contained in the test specimen after the exposure has ceased.
Note 2: See Appendix X4 for additional information regarding this test method and predicted skin burn injury.
1.2 This test method is used to measure and describe the response of materials, products, or assemblies to heat under controlled conditions, but does not by itself incorporate all factors required for fire hazard or fire risk assessment of the materials, products, or assemblies under actual fire conditions.
1.3 The values stated in SI units are to be regarded as standard. The values given in parentheses are mathematical conversions to inch-pound or other units that are commonly used for thermal testing.
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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.
1.5 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: F1939 − 15 (Reapproved 2020)
Standard Test Method for
Radiant Heat Resistance of Flame Resistant Clothing
Materials with Continuous Heating
This standard is issued under the fixed designation F1939; 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.
1. Scope mendations issued by the World Trade Organization Technical
Barriers to Trade (TBT) Committee.
1.1 This test method rates the non-steady state thermal
resistance or insulating characteristics of flame resistant cloth-
2. Referenced Documents
ing materials subjected to a continuous, standardized radiant
2.1 ASTM Standards:
heat exposure.
D123 Terminology Relating to Textiles
1.1.1 Thistestmethodisnotapplicabletoclothingmaterials
D1776/D1776M Practice for Conditioning and Testing Tex-
that are not flame resistant.
tiles
NOTE 1—The determination of a clothing material’s flame resistance
D1777 Test Method for Thickness of Textile Materials
shall be made prior to testing and done in accordance with the applicable
D3776/D3776M Test Methods for Mass Per Unit Area
performance standard, specification standard, or both, for the clothing
material’s end use. (Weight) of Fabric
E457 Test Method for Measuring Heat-Transfer Rate Using
1.1.2 This test method does not predict skin burn injury
a Thermal Capacitance (Slug) Calorimeter
from the standardized radiant heat exposure, as it does not
F1494 Terminology Relating to Protective Clothing
account for the thermal energy contained in the test specimen
2.2 ASTM Special Technical Publications:
after the exposure has ceased.
ASTM Report ASTM Research Program on Electric Arc
NOTE 2—See Appendix X4 for additional information regarding this
Test Method Developments to Evaluate Protective Cloth-
test method and predicted skin burn injury.
ingFabric;ASTMF18.65.01TestingGroupReportonArc
1.2 This test method is used to measure and describe the
Testing Analysis of the F1959 Standard Test Method—
response of materials, products, or assemblies to heat under
Phase I
controlled conditions, but does not by itself incorporate all
ASTM Manual 12 Manual on the Use of Thermocouples in
factors required for fire hazard or fire risk assessment of the
Temperature Measurement
materials, products, or assemblies under actual fire conditions.
1.3 The values stated in SI units are to be regarded as
3. Terminology
standard. The values given in parentheses are mathematical
3.1 Definitions:
conversions to inch-pound or other units that are commonly
3.1.1 break-open, n—in testing thermal protective
used for thermal testing.
materials, a material response evidenced by the formation of a
1.4 This standard does not purport to address all of the
hole in the test specimen during the thermal exposure that may
safety concerns, if any, associated with its use. It is the
result in the exposure energy in direct contact with the heat
responsibility of the user of this standard to establish appro-
sensor.
priate safety, health, and environmental practices and deter-
3.1.2 charring, n—the formation of a carbonaceous residue
mine the applicability of regulatory limitations prior to use.
as the result of pyrolysis or incomplete combustion.
1.5 This international standard was developed in accor-
3.1.3 dripping,n—amaterialresponseevidencedbyflowing
dance with internationally recognized principles on standard-
of the polymer.
ization established in the Decision on Principles for the
3.1.4 embrittlement, n—the formation of a brittle residue as
Development of International Standards, Guides and Recom-
a result of pyrolysis or incomplete combustion.
ThistestmethodisunderthejurisdictionofASTMCommitteeF23onPersonal
Protective Clothing and Equipment and is the direct responsibility of Subcommittee
F23.80 on Flame and Thermal. For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Current edition approved Oct. 1, 2020. Published October 2020. Originally contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
approved in 1999. Last previous edition approved in 2015 as F1939 – 15. DOI: Standards volume information, refer to the standard’s Document Summary page on
10.1520/F1939-15R20. the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
F1939 − 15 (2020)
3.1.5 heat flux, n—the thermal intensity indicated by the materials, or a comparison of different materials used in
amountofenergytransmitteddividedbyareaandtime;kW/m flame-resistant clothing for workers exposed to radiant thermal
(cal/cm s). hazards.
3.1.6 ignition, n—the initiation of combustion.
5.2 This test method evaluates a material’s heat transfer
properties when exposed to a continuous and constant radiant
3.1.7 melting, n—a material response evidenced by soften-
heat source. Air movement at the face of the specimen and
ing of the polymer.
around the calorimeter can affect the measured heat transferred
3.1.8 non-steady state thermal resistance, n—in testing of
due to forced convective heat losses. Minimizing the air
thermal protective materials, a quantity expressed as the
movement around the specimen and test apparatus will aid in
time-dependent difference between the incident and exiting
the repeatability of the results.
thermal energy values normal to and across two defined
5.3 This test method maintains the specimen in a static,
parallel surfaces of an exposed thermal insulative material.
vertical position and does not involve movement, except that
3.1.9 radiant heat resistance (RHR), n—in testing of ther-
resulting from the exposure.
mal protective materials, the cumulative amount of thermal
exposure energy identified by the intersection of the measured 5.4 This test method specifies two standard sets of exposure
2 2 2
time-dependent heat transfer response through the subject conditions: 21 kW/m (0.5 cal/cm s) and 84 kW/m
material to a time-dependent, empirical performance curve, (2.0 cal⁄cm s). Either can be used.
2 2
expressed as a rating or value; kJ/m (cal/cm ). 5.4.1 If a different set of exposure conditions is used, it is
likely that different results will be obtained.
3.1.10 response to heat exposure, n—in testing the thermal
5.4.2 The optional use of other conditions representative of
resistance of thermal protective materials, the observable
the expected hazard, in addition to the standard set of exposure
response of the material to the energy exposure as indicated by
conditions, is permitted. However, the exposure conditions
break-open, melting, dripping, charring, embrittlement,
used must be reported with the results along with a determi-
shrinkage, sticking, and ignition.
nation of the exposure energy level stability.
3.1.11 shrinkage, n—a decrease in one or more dimensions
5.5 This test method does not predict skin burn injury from
of an object or material.
the standardized radiant heat exposure.
3.1.12 sticking, n—a material response evidenced by soft-
ening and adherence of the material to the surface of itself or NOTE 4—See Appendix X4 for additional information regarding this
test method and predicted skin burn injury.
another material.
3.1.13 For the definitions of protective clothing terms used
6. Apparatus and Materials
in this method, refer to Terminology F1494, and for other
6.1 General Arrangement—The apparatus consists of a
textile terms used in this method, refer to Terminology D123.
vertically oriented radiant heat source, specimen holder
assembly, protective shutter, sensor assembly, and data
4. Summary of Test Method
acquisition/analysis system. The general arrangement of the
4.1 A vertically positioned test specimen is exposed to a
radiant heat source, specimen holder, and protective shutter of
radiant heat source with an exposure heat flux of either (a)
a suitable apparatus is shown in Fig. 1.
2 2 2 2
21 kW⁄m (0.5 cal/cm s), or (b) 84 kW/m (2 cal/cm s).
6.1.1 Radiant Heat Source—A suitable, vertically oriented
radiant heat source is shown in Fig. 1. It consists of a bank of
NOTE 3—Other exposure heat flux values are allowed. The test facility
shall verify the stability of the exposure level over the material’s exposure five, 500 W infrared, tubular, translucent quartz lamps having
time interval (used to determine the radiant heat resistance value) and
a 127-mm (5.0-in.) lighted length and a mean overall length of
include this in the test results report.
222 mm (8 ⁄4 in.). The lamps are mounted on 9.5 6 0.4-mm
3 1
4.2 The transfer of heat through the test specimen is
( ⁄8 6 ⁄64-in.) centers so that the lamp surfaces are approxi-
measured using a copper slug calorimeter. The change in
mately 0.4 mm ( ⁄64 in.) apart. The bank or array of lamps are
temperature versus time is used, along with the known thermo-
mounted and centered behind a 63.5 by 140-mm (2 ⁄2 by
1 1
physical properties of copper to determine the respective
5 ⁄2-in.)cut-outthatispositionedinthecenterofa12.7mm( ⁄2
3 1
thermal energy delivered.
in.) thick, 86 mm (3 ⁄8 in.) wide by 292 mm (11 ⁄2 in.) long,
high-temperature insulating board as shown in Fig. 2. The
4.3 A radiant heat resistance rating of the test specimen is
quartz lamps shall be heated electrically, and the power input
determined as the intersection of the time-dependent cumula-
controlled by means of a rheostat or variable power supply
tive radiant heat response as measured by the calorimeter to a
having a capacity of at least 25 A.
time-dependent, empirical performance curve identified in
6.1.1.1 Setting and monitoring the voltmeter readout on a
10.9.
voltage-controlled variable power supply is one method to
4.4 Subjective observations of the thermal response of
calibrate and monitor the exposure level during the testing on
tested specimens are optionally noted.
a system so equipped. A voltmeter, accurate to 61V, is
typically installed with the appropriate load circuit to indicate
5. Significance and Use
lamp operating power.
5.1 This test method is intended for the determination of the 6.1.1.2 Any covers or guards installed on the quartz lamp
radiant heat resistance value of a material, a combination of assembly shall be designed such that any convective energy
F1939 − 15 (2020)
FIG. 1 General Expanded View of a Compliant Radiant Resistance Performance Test Apparatus (See Figures 2, 3, and 4 for specific
item details)
FIG. 2 Detailed View of Position of Quartz Lamps on Thermal Insulating Board
F1939 − 15 (2020)
to the test specimen is 25.4 6 0.4 mm (1.0 6 ⁄64 in.). The rear
holder plate thickness is 0.9 6 0.05 mm (0.036 6 0.002 in.)
and includes a bracket to hold the copper calorimeter sensor
assembly. This rear plate holds the specimen in place so that it
covers the complete cutout section (see typical designs shown
in Figs. 3 and 4). Several specimen holders are recommended
to facilitate testing.
NOTE 7—The copper calorimeter sensor assembly holder plate bracket
isconstructedsuchthatthecalorimeterassemblyisinareproduciblefixed
vertical position when installed and is held flush and rigidly against the
rear holder plate.
6.1.3 Protective Shutter—A protective shutter, as shown in
Fig. 3, is placed between the radiant energy source and the
specimen. The protective shutter blocks the radiant energy just
prior to the exposure of a specimen. Manual or mechanically
operated shutter designs are allowed with and without water-
cooling.
FIG. 3 Detailed View of a Compliant Radiant Protective Perfor-
mance Test Apparatus Showing Holder with Window, Manual
6.1.4 Rheostat or Variable Power Supply—Astandard labo-
Shutter Plate, and Specimen Holder with Calorimeter Brackets (A
ratory rheostat or appropriate power supply with a capacity of
magnet/tab arrangement is shown as an equipment design op-
at least 25 A, which is capable of controlling the output
tion to hold the specimen holder to the assembly)
intensity of the tubes over the range specified in 4.1.
6.1.5 Sensor—The radiant heat sensor is a 4 6 0.05 cm
generated is not allowed to impinge on the sample specimen
diameter circular copper slug calorimeter constructed from
(vertical, umimpeded ventilation is required).
electrical grade copper with a mass of 18 6 0.05 g (prior to
drilling) with a single iron-constantan (ANSI Type J) thermo-
NOTE 5—Radiant measurement systems designed with closed lamp
assembly covers and covers with minimal ventilation have been found to couple wire bead (0.254 mm wire diameter or finer—
exhibit large measurement biases in round robin testing.
equivalent to 30 AWG) installed as identified in 6.1.5.2 and
3,4
NOTE 6—Transite monolithic, non-asbestos fiber cement board has
shown in Fig. 5 (see Test Method E457 for information
been found to be effective as a high-temperature insulating board.
regarding slug calorimeters). The sensor holder shall be con-
6.1.2 Specimen Holder Assembly—A specimen holder and
structed from non-conductive, heat-resistant material with a
holder plate with a 64 by 152-mm (2 ⁄2 by 6-in.) center cut-out
thermal conductivity value of ≤0.15 W/m·K, high temperature
is positioned so that the distance from the nearest lamp surface
stability, and resistance to thermal shock. The board shall be
nominally 1.3 cm (0.5 in.) or greater in thickness and meet the
specimen holder assembly requirements of 6.1.2. The sensor is
Thesolesourceofsupplyofthistypeofproductknowntothecommitteeatthis
time is BNZ Materials, Inc., 6901 South Pierce Street, Suite 260, Littleton, CO
held into the recess of the board using three straight pins,
80128, Ph: 800-999-0890.
trimmed to a nominal length of 5 mm, by placing them
If you are aware of alternative suppliers, please provide this information to
equidistant around the edge of the sensor so that the heads of
ASTM International Headquarters. Your comments will receive careful consider-
the pins hold the sensor flush to the surface.
ation at a meeting of the responsible technical committee, which you may attend.
FIG. 4 Sample Position Example—Top View Enlargement
F1939 − 15 (2020)
NOTE 1—Secure the copper disk into the supporting insulation board with three or four sewing pins cut to 9.5 mm (0.375 in.) in length (positioned
around the periphery so that the sewing pin heads hold the disk into the board).
FIG. 5 Radiant Heat Resist
...
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