ASTM F2178/F2178M-23a

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: F2178/F2178M − 23a
Standard Specification for
Arc Rated Eye or Face Protective Products
This standard is issued under the fixed designation F2178/F2178M; 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 1.5 This standard shall not be used to describe or appraise
the fire hazard or fire risk of materials, products, or assemblies
1.1 This product specification is used to determine the arc
under actual fire conditions. However, results of this test may
rating and specify the requirements for products intended for
be used as elements of a fire assessment which takes into
use as eye or face protection for workers exposed to electric
account all of the factors which are pertinent to an assessment
arcs. The arc rating is determined in the test with an arc which
2 2 of the fire hazard of a particular end use.
has a heat flux value of 2100 kW/m [50 cal/cm /s]. Products
1.6 This standard does not purport to address all of the
are tested as sold.
safety concerns, if any, associated with its use. It is the
1.2 The products covered by this standard are in the form of
responsibility of the user of this standard to establish appro-
faceshields attached to the head by protective helmets (hard
priate safety, health, and environmental practices and deter-
hats), headgear, hood assemblies, safety spectacles or goggles.
mine the applicability of regulatory limitations prior to use.
Faceshields, safety spectacles or goggles are tested with or
For specific hazards see Section 11.
without other face and head protective products, for example,
1.7 This international standard was developed in accor-
sock hoods, balaclavas, sweat shirt hoods or jacket hoods.
dance with internationally recognized principles on standard-
1.2.1 Fabric layers used in the design of face protection
ization established in the Decision on Principles for the
products such as in hood, neck guards, balaclava, meet the
Development of International Standards, Guides and Recom-
requirements of Specification F1506. When fabrics are de-
mendations issued by the World Trade Organization Technical
signed into the protection provided for eye or face protective
Barriers to Trade (TBT) Committee.
products, the arc rating of fabric system is first determined by
Test Method F1959/F1959M.
2. Referenced Documents
1.2.2 The arc rating of the eye or face protective product
which requires fabric to provide protection to the face or head
2.1 ASTM Standards
will not be higher than the lower arc rating of either the fabric
C177 Test Method for Steady-State Heat Flux Measure-
system or the shield/visor assembly.
ments and Thermal Transmission Properties by Means of
the Guarded-Hot-Plate Apparatus
1.3 The values stated in SI units shall be regarded as
D123 Terminology Relating to Textiles
standard except as noted. Within the text, alternate units are
D4391 Terminology Relating to The Burning Behavior of
shown in brackets. The values stated in each system may not be
Textiles
exact equivalents; therefore, alternate systems must be used
F1494 Terminology Relating to Protective Clothing
independently of the other. Combining values from the systems
F1506 Performance Specification for Flame Resistant and
described in the text may result in nonconformance with the
Electric Arc Rated Protective Clothing Worn by Workers
method.
Exposed to Flames and Electric Arcs
1.4 This standard does not purport to describe or appraise
F1959/F1959M Test Method for Determining the Arc Rating
the effect of the electric arc fragmentation or propulsion of
of Materials for Clothing
parts of equipment or molten metal splatter, deposited from the
2.2 ANSI/IEEE Standards:
pressure wave containing molten metals and possible frag-
IEEE Standard Dictionary of Electrical and Electronics
ments of other materials except to the extent that heat energy
Terms
transmission due to these arc explosion phenomena is reduced
by test specimens.
1 2
This specification is under the jurisdiction of ASTM Committee F18 on For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Electrical Protective Equipment for Workers and is the direct responsibility of contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
Subcommittee F18.65 on Wearing Apparel. Standards volume information, refer to the standard’s Document Summary page on
Current edition approved Sept. 1, 2023. Published September 2023. Originally the ASTM website.
approved in 2002. Last previous edition approved in 2023 as F2178/F2178M – 23. Available from Institute of Electrical and Electronics Engineers, Inc. (IEEE),
DOI: 10.1520/F2178_F2178M-23A. 445 Hoes Ln., Piscataway, NJ 08854-4141, http://www.ieee.org.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
F2178/F2178M − 23a
ANSI/ISEA Z87.1 American National Standard for Occu- 3.2.8.2 Discussion—This rating may also be set to any value
pational and Educational Personal Eye and Face Protec- below the ATPV/EBT and meeting the ignition withstand to
tion Devices assure the product is safe for use with no ignition or melting
and dripping at or below the arc rating of the final product. This
3. Terminology
AR could also be set at the fabric arc rating or lower due to
Lim
an add-on such as a specialized adapter to place the faceshield
3.1 For definitions of other textile terms used in this
further from the face for respirator use, or due to the ignition of
specification, refer to Terminologies D123, D4391, F1494 and
a component in which demonstrates ignition at a level near the
the IEEE Standard Dictionary of Electrical and Electronics
arc rating such as a hook and loop closure, rivets, a flashlight
Terms.
or a fan system.
3.2 Definitions:
3.2.9 arc voltage, n—voltage across the gap caused by the
3.2.1 afterflame, n—persistent flaming of a material after the
current flowing through the resistance created by the arc gap
ignition source has been removed.
(V).
3.2.2 afterflame time, n—the length of time for which a
3.2.10 asymmetrical arc current, n—the total arc current
material continues to flame after the ignition source has been
produced during closure; it includes a direct component and a
removed.
symmetrical component, A.
3.2.3 arc duration, n—time duration of the arc, s.
3.2.11 blowout, n—the extinguishing of the arc caused by a
3.2.4 arc energy, n—sum of the instantaneous arc voltage
magnetic field.
values multiplied by the instantaneous arc current values
3.2.12 breakopen, n—in electric arc testing, a material
multiplied by the incremental time values during the arc, J.
response evidenced by the formation of one or more holes in
3.2.5 arc gap, n—distance between the arc electrodes, cm
the material which may allow thermal energy to pass through
[in.].
material.
3.2.6 arc rating, n—value attributed to materials that de-
3.2.12.1 Discussion—The specimen is considered to exhibit
scribes their performance to exposure to an electric arc
2 2
breakopen when any hole in the material or fabric is at least
discharge, J/cm [cal ⁄cm ].
2 2
1.6 cm [0.5 in. ] in area or at least 2.5 cm [1.0 in.] in any
3.2.6.1 Discussion—The arc rating is expressed in
2 2
dimension. For textile materials, single threads across the
J/cm [cal ⁄cm ] and is derived from the determined value of
opening or hole do not reduce the size of the hole for the
ATPV or EBT (should a material system exhibit a breakopen
purposes of this test method. In multiple layer specimens, if
response below the ATPV value) or the Arc Rating Limit. It can
some of the layers are ignitable, breakopen occurs when these
be expressed in short form as either AR , AR or AR .
ATPV EBT Lim
layers are exposed.
3.2.7 arc thermal performance value (ATPV), n—in arc
3.2.12.2 Discussion—A system having multi-layer fabric or
testing, the incident energy of a fabric or material that results
multi-layer shields may exhibit formation of holes (ablation) of
in 50 % probability that sufficient heat transfer through the
the outermost layers. Breakopen is not considered attained
specimen is predicted to cause the onset of a second-degree
until the formation of one or more holes has occurred in the
skin burn injury based on the Stoll curve.
innermost protective layer. This can include a hardhat.
3.2.8 arc rating limit (AR ), n—the maximum arc thermal
Lim
3.2.12.3 Discussion—Breakopen of a fabric which is on a
energy protection that has been assigned to the product based
hood system is only considered breakopen if the breakopen
on the manufacturer’s specifications after verification with
allows a clear line of sight to the mannequin. For instance, if
testing or limits of detection of the test method.
fabric is covering the interfacing between the hood and a
3.2.8.1 Discussion—For hoods, the AR could be a limit
Lim
hardhat it will only be considered breakopen if a clear line of
made by the test laboratory based on the equipment limits of
sight to any non-arc rated layer of fabric or the test mannequin.
2 2
the energy exposure (418.4 J/cm [100 cal/cm ] in many
3.2.13 breakopen threshold energy (EBT), n—the incident
laboratories) or the producer may deliberately specify an
energy on a fabric or material that results in a 50 % probability
incident energy value, which may be lower than the arc rating
of breakopen.
(ATPV or EBT) of the material or material assembly for the
2 2
3.2.13.1 Discussion—This is the value in J/cm [cal/cm ]
evaluation of the finished product. In this case, testing may
determined by use of logistic regression analysis representing
deliberately be carried out only at incident energy exposures
the energy at which breakopen of the layer occurred.
lower than the projected arc rating of the material or material
3.2.14 dripping, n—in electric arc testing, a material re-
assembly provided the system meets the visual assessment and
sponse evidenced by flowing of a specimen’s material of
all performance criteria.
composition.
3.2.14.1 Discussion—Dripping is exhibited by either the
Available from American National Standards Institute (ANSI), 25 W. 43rd St.,
fabric material or faceshield material, or other parts of eye or
4th Floor, New York, NY 10036, http://www.ansi.org.
Derived from Stoll, A. M., and Chianta, M. A., “Method and Rating System for
face protective products.
Evaluations of Thermal Protection,” Aerospace Medicine, Vol 40, 1969, pp.
3.2.15 heat flux, n—the thermal intensity indicated by the
1232-1238 and Stoll, A. M., and Chianta, M. A., “Heat Transfer through Fabrics as
amount of energy transmitted per area and time W/m [cal/
Related to Thermal Injury,” Transactions – New York Academy of Sciences, Vol
33(7), Nov. 1971, pp. 649-670. cm s].
F2178/F2178M − 23a
3.2.16 incident energy monitoring sensors, n—sensors 5.2 Scratch Resistance—Manufacturer shall certify if
mounted on each side of each head, using calorimeters, not scratch resistant coating is applied to window of eye or face
covered by specimens, used to measure incident energy. protective product.
3.2.17 incident exposure energy (E ), n—in arc testing, the
5.3 Fogging Resistance—Manufacturer shall certify if anti-
i
total incident energy delivered to monitor calorimeter sensors fog coating is applied to window of eye or face protective
2 2
from the arc exposure, J/cm [cal/cm ].
product.
5.4 For Hoods, Fabric Material Physical Requirements—
3.2.17.1 Discussion—in an arc test exposure, incident ex-
Fabric Material in the hood shall meet the requirements of
posure energy for a specimen is the average of the measured
Specification F1506.
incident energy from the respective two monitor sensors
adjacent to the test specimen.
6. Performance Requirements
3.2.18 material response, n—material response to an elec-
tric arc is indicated by the following terms: breakopen, melting, 6.1 The stitching, thread, findings, fasteners, or other com-
dripping, deformation, afterflame time, shrinkage, and electric ponents used to manufacture the eye or face protective product
arc ignition. shall not degrade the flame resistance or thermal performance
of the eye or face protective products.
3.2.19 melting, n—in arc testing, a material response evi-
denced by softening of the material. 6.2 Eye or face protective products shall conform to the
requirements of Section 7 for thermal resistance to an electric
3.2.20 peak arc current, n—maximum value of the AC arc
arc exposure.
current, A.
6.3 The results for all performance requirements and sub-
3.2.21 RMS arc current, n—root mean square of the AC arc
jective material evaluations shall be provided. Subjective
current, A.
material evaluations for at least two arc exposures at or above
3.2.22 shrinkage, n—in testing eye or face protective
the arc rating shall be reported. This report shall be made
products, a material response evidenced by reduction in
available to the purchaser of eye or face protective product
specimen size.
meeting this specification by the eye or face protective product
3.2.23 X/R ratio, n—the ratio of system inductive reactance
manufacturer.
to resistance. It is proportional to the L/R ratio of time constant,
NOTE 1—Example tables for reporting the test results and subjective
material evaluation are shown in Table 1 and Table 2.
and is, therefore, indicative of the rate of decay of any DC
offset. A large X/R ratio corresponds to a large time constant
6.4 Products tested for full face protection shall have an
and a slow rate of decay.
interface that is designed to prevent burns to parts of the face
not represented by sensors on the test mannequin head.
4. Ordering Information NOTE 2—If goggles as part of a full face protective system are tested for
full face protection, the system shall not have gaps in areas which are not
4.1 The following items should be considered by the pur-
sensored, such as the nose, around the eyes, etc. The interface shall
chaser when buying eye or face protective products under this
include the full face and be designed to provide the same performance
over the whole face area from the chin area all over the head.
specification and included, as necessary, in purchasing docu-
ments:
6.5 Products tested for full face protection which have
4.1.1 Arc Rating of the eye or face protective products,
removable parts shall be labeled or designed to make removal
2 2
J/cm [cal/cm ],
or use without proper assembly clear to the end user. Remov-
4.1.2 Type of material in the window of the eye or face
able faceshields, faceplates, goggles or other systems and the
protective product, properly matched hood or other protective parts of the system
4.1.3 Thickness of the eye or face protective product, mm shall be designed and marked in such a way that the proper
[in.], replacement parts are evident to the end user.
2 2
4.1.4 Type and weight, g/m [oz ⁄yd ] of hood fabric mate-
7. Thermal Performance Requirements
rial in the eye or face protective product for hoods,
4.1.5 Type and material of fasteners (buttons, snaps, zippers
7.1 The eye or face protective product shall be tested for
or hook and loop fasteners),
thermal resistance to an electric arc exposure by the use of this
4.1.6 Style and design or catalog number, test method. Test parameters shall be 8 kA 6 1 kA arc current,
4.1.7 Special identification markings (optional), and 30 cm [12 in.] electrode gap, stainless steel electrodes, 30 cm
[12 in.] distance between the arc center line and the mouth
4.1.8 Notation of conformance to this specification.
sensor surface. Modified test parameters may also be used and
the results reported on an optional basis.
5. Physical Requirements
NOTE 3—This test method is a design test.
5.1 The faceshield window, safety spectacle or goggle in the
7.2 For hoods, the arc rating of the fabric material shall be
eye or face protective product shall meet the requirements of
determined according to Test Method F1959/F1959M and
ANSI/ISEA Z87.1. Requirements include: Flammability, Cor-
reported.
rosion Resistance, Optical, Cleanability, Markings,
Penetration, Minimum Thickness, Drop ball, High Mass, and 7.3 The arc rating of the eye or face protective product shall
2 2
High Velocity. be equal to or greater than 4.0 cal/cm [16.74 J/cm ].
F2178/F2178M − 23a
TABLE 1 Eye or Face Protective Product Performance Requirements Test Report
Company Issuing Report ____________________________________________________________
Date of Report _____________________
Sample description for the eye or face protective product
Eye or face protective product type, hood, faceshield or other ____________________________________________________
Composition of window material ________________________________________________
Coatings on window (if applicable) ____________________________________________________
Thickness of window, mm [in.] ________________________________
2 2
Nominal weight of hood fabric (all layers) (if applicable), oz/yd [g/m ] ________________________________
2 2
Actual weight of hood fabric as tested (if applicable), oz/yd [g ⁄m ] _______________________________________________
Color of hood fabric if applicable __________________________________________________________________
ASTM F2178 Requirement Material Performance
The window in the eye or face protective products Requirements Include: Ignition assessment, Certification by manufacturer that window in the eye
shall meet the requirements of ANSI Z87.1 Optical, Markings, Penetration, Minimum or face protective product meets the requirements of
thickness, Drop ball, High mass and High velocity ANSI/ISEA Z87.1
Scratch resistance Report Only Certification by manufacturer that scratch resistant
no minimum value coating is applied to window of eye or face protec-
tive product
Fogging resistance Report Only Certification by manufacturer that anti-fog coating is
no minimum value applied to window of eye or face protective product
For Hoods, Fabric Material Hood fabric material shall meet the requirements Certification by Eye or Face Protective Product
of Specification F1506 Manufacturer that fabric material in hood meets the
requirements of Specification F1506
Stitchings, thread, findings, fasteners or other Certification by Eye or Face Protective Product
components shall not degrade the flame resis- Manufacturer that stitchings, thread, findings, fasten-
tance or thermal performance of the eye or face ers or other components do not degrade flame re-
protective product sistance or thermal performance of the eye or face
protective product
2 2
Arc Rating of eye or face protective product Report Arc Rating _____ J/cm ____ cal/cm
2 2
$ 4.0 cal/cm [16.74 J/cm ] Arc Rating (AR ) or Arc Rating (AR ) or Arc
ATPV EBT
Rating Limit (AR )
Lim
2 2
For hood systems, Arc Rating of fabric material Report Arc Rating _____ J/cm _____ cal/cm
2 2
$ 4.0 cal/cm [16.74 J/cm ] Arc Rating (AR ) or Arc Rating (AR ) or Arc
ATPV EBT
Rating Limit (AR )
Lim
TABLE 2 Subjective Material Evaluation of Eye or Face Protective
7.6 For Procedure B—System having an arc rating equal or
Products 2 2
higher than 20 cal/cm [83.7 J/cm ] shall not exhibit ignition or
Subjective Material Evaluations
melting and dripping in any of the exposures in the verification
at
testing.
or above Arc Rating
Arc Exposure Arc Exposure
# 1 # 2
8. Summary of Test Method
Incident Energy, cal/cm
8.1 This test method determines the heat transmitted or
After flame time, s
Breakopen (yes/no) and size in cm [in.]
transported across a material when exposed to the heat energy
Melting (yes/no)
from an electric arc. This heat transport response is compared
Dripping (yes/no)
to the Stoll curve.
Deformation of window (yes/no)
Fabric Shrinkage, %
8.1.1 Products are mounted on the standard mannequin head
Electric Arc Ignition (yes/no)
containing copper slug calorimeters inserted in the eyes,
mouth, and chin positions. During this procedure, the amount
of heat energy transferred by the specimen eye or face
protective products is measured during and after exposure to an
7.4 Systems having an arc rating below 20 cal ⁄cm
electric arc.
[83.7 J ⁄cm ] shall not exhibit ignition or melting and dripping
8.1.2 The thermal energy exposure and heat transport re-
2 2
below 20 cal ⁄cm [83.7 J ⁄cm ].
sponse of the test specimen(s) are measured with copper slug
7.5 For Procedure A—System having an arc rating equal or calorimeters. The change in temperature versus time is used,
2 2
higher than 20 cal/cm [83.7 J/cm ] shall not exhibit ignition or
along with the known thermo-physical properties of copper to
melting and dripping within the mix zone of the iterative determine the respective thermal energies delivered to and
procedure. through the specimen(s).
F2178/F2178M − 23a
8.2 This procedure incorporates incident energy monitoring 9.6 The purchaser has the option to perform or have
sensors. performed any of these tests to verify the performance of the
eye or face protective product. Claims for failure to meet the
8.3 Product and material performance for this procedure are
specification are subject to verification by the manufacturer.
determined by using the incident energy generated by the arc
9.7 In addition to the standard set of exposure conditions,
flash measured by monitor sensors to compare the energy
transferred by or through the test specimen(s) and measured by other conditions representative of the expected hazard may be
used and shall be reported should this data be cited.
calorimeters on the mannequin head and compared to the Stoll
Curve Criteria to predict a protective value called an Arc
Rating. 10. Apparatus
10.1 General Arrangement for Determining Rating Using
8.4 Alternatively, if the Stoll Curve Criteria is not met, the
standard uses the EBT or AR to set the Arc Rating. Sensor Heads and Monitor Sensors—The test apparatus shall
Lim
consist of supply bus, arc controller, recorder, arc electrodes,
8.5 Product and material responses are further described by
two (or optionally three) four-sensor heads, and four (or
recording the observed effects of the electric arc exposure on
optionally six) incident energy monitoring sensors. The arc
the specimens using the terms in the Report section.
exposure shall be monitored with two incident energy-
8.6 Accessories for eyes and face protective products such
monitoring sensors for each sensored head.
as air supply or cooling devices, lamps, hearing protection or
10.2 Head Construction—Each four-sensor head and each
any other accessory attached to the protective product are
monitor sensor holder shall be constructed from electrically
evaluated for ignition, melt and drip in evaluating the protec-
insulating and flame- and heat-resistant material. The head
tion level of the product.
form shall have four sensors mounted as shown in Fig. 1. The
chin sensor shall be in the horizontal plane (perpendicular to
9. Significance and Use
the plane of the eye and mouth) under the chin as shown in Fig.
9.1 This specification’s test method is used to determine an 1. The chin sensor shall protrude below the lowest point of the
arc rating for eye or face protective products, including face chin by 3 mm [ ⁄8 in.].
shields, safety spectacles, goggles, or other applicable portions
10.3 Sensor Construction—The sensor mount used to hold
of the complete product that are required to meet the current
the calorimeter shall be constructed from a thermally stable
version of ANSI/ISEA Z87.1. This excludes the textile or parts
heat-resistant material with a minimum thermal conductivity
of the hood assemblies or other rated products that are not
value as indicated in Table 3 to prevent unwanted heat
testable by ANSI/ISEA Z87.1. This standard does not measure
conduction (such as Fire-Resistant Structural Insulation or
optical and impact properties (see ANSI/ISEA Z87.1) but does
equivalent). The dimensions of the sensor mount are shown in
specify requirements for optical and impact properties in
Fig. 2.
accordance with that standard.
10.3.1 The calorimeter shall be constructed from electrical
9.2 The test method is used to measure and describe the grade copper with purity greater than 99.9 %, UNS C11000.
The copper disc shall have a thickness of 1.6 mm 6 0.1 mm,
properties of materials, products, or assemblies in response to
convective and radiant energy generated by an electric arc a diameter of 40 mm 6 0.1 mm and a mass of 18 g 6 0.5 g.
under controlled laboratory conditions and does not purport to The thickness, diameter and mass of each copper disc shall be
predict damage from light other than the thermal aspects measured to determine the actual response coefficient for each
measured. calorimeter that is used in heat capacity calculations. In the
case of a group of copper discs having an average mass/area
9.3 The specification’s test method is intended for the
ratio within 60.008 g/cm , the average value for the group of
determination of the arc rating of a product/design, intended
calorimeters may be used.
for use as eye or face protection for workers exposed to electric
10.3.2 A type K (NiCr-NiAl) thermocouple having a cross
arcs. For whole body protection, additional personal protective
sectional area of 0.05 mm (No. 30 AWG) or equivalent shall
equipment (PPE) will be required for parts not covered by this
be used to construct the calorimeter. The thermocouple shall be
standard.
installed inside the hole of the copper disc as shown in Fig. 6.
9.3.1 Because of the variability of the arc exposure, differ-
The tip of the thermocouple shall be bare for the full length
ent heat transmission values may be observed at individual
inside the copper disc. Copper filler material may be used to
sensors. The results of each sensor are evaluated in accordance
mechanically secure the thermocouple tip in place. The ther-
with Section 16.
mocouple wires shall be separated immediately upon exiting
9.4 This test method maintains the specimen in a static,
the copper disc.
vertical position and does not involve movement except that
10.3.3 The calorimeter shall be inserted into the cavity of
resulting from the exposure.
the sensor mount. The copper disc shall be flush with the
surface of the sensor material. The copper disc can be secured
9.5 Different exposure conditions produce different incident
in place with stainless steel pins (3 or 4) spaced around the
energies and different heat fluxes. This standard exposure is
circumference of the disc.
used for comparison of products and hazard assessment meth-
ods may use multiplication factors or other means for deter-
NOTE 4—Stainless steel sewing pins cut to a few millimeters have been
mining protection. used successfully.
F2178/F2178M − 23a
FIG. 1 Mannequin Head and Head Sensor Locations
TABLE 3 Thermal Conductivity in accordance with Test Method
Fabric; ASTM F18.65.01 Testing Group Report on Arc Testing
C177 at Various Mean Temperatures
Analysis of the F1959/F1959M Standard Test Method—Phase
Thermal Conductivity
1.”
Temperature
Btu-in./ft , h, °F [W/m °K]
10.3.5 Alternate calorimeters are permitted for use as moni-
75 °F [24 °C] 1.15 [0.17]
tor sensors provided they are calibrated and have a similar
400 °F [205 °C] 1.13 [0.16]
600 °F [316 °C] 1.15 [0.17]
response. The use of a different thermocouple junction, ex-
800 °F [425 °C] 1.16 [0.17]
posed surface area, slug material, and mass is allowed; their
1000 °F [538 °C] 1.17 [0.17]
performance shall be documented in the test results.
10.4 Arrangement of the Four-Sensor Heads and Monitor
Sensors—The standard test set up is three four-sensor heads
spaced at 120° around the arc (Fig. 3). Each head shall be
10.3.4 The exposed surface of the copper slug calorimeters
located vertically to the arc electrodes as shown in Fig. 4 at a
shall be painted with a thin coating of a flat black high-
horizontal distance of 300 mm 6 5 mm [12 in.] from the mouth
temperature spray paint with an emissivity of >0.9. The painted
calorimeter to the center of the electrodes. Each four-sensor
sensor shall be dried before use and present a uniformly
head shall have two incident energy monitoring sensors. One
applied coating (no visual thick spots or surface irregularities).
monitoring sensor shall be located on each side of each
Note that an external heat source, for example, an external heat
four-sensor head as shown in Fig. 5 at a position and angle
lamp, may be required to completely drive off any remaining
indicated in Table 4. The face of the monitor sensors shall be
organic carriers in a freshly painted surface.
perpendicular to a radius line from the center of the electrode
10.3.4.1 An evaluation of the emissivity of the painted
to the center of the monitor sensor.
calorimeters used in this test method was conducted by
Committee F18; “ASTM Research Program on Electric Arc 10.4.1 The actual distance of the monitor sensors and
Test Method Development to Evaluate Protective Clothing four-sensor head shall be measured and the value used to
F2178/F2178M − 23a
FIG. 2 Sensor Mount
FIG. 3 Location of Mannequin Heads
FIG. 4 Vertical Location of Heads to Arc Electrodes
determine the multiplier for the incident energy calculation.
The multiplier factor shall be the square of the ratio of the
actual distance of the monitor sensor divided by the actual
distance of the four-sensor head to which the monitor is 305 mm and the incident energy monitors at 340 mm, the
positioned. Example: When having the four-sensor head at incident correction factor is (340/305) = 1.24.
F2178/F2178M − 23a
10.4.3 Each four-sensor head may be mounted on the
mannequin body to simulate a human body. Any clothing on
the mannequin (if used) shall be reported.
10.5 Supply Bus and Electrodes—A typical arrangement of
the supply bus and arc electrodes is shown in Fig. 4. The arc
shall be in a vertical position as shown.
10.5.1 Electrodes—Make the electrodes from stainless steel
(Alloy Type 303 or Type 304) rod of a nominal 19 mm
[0.75 in.] diameter. Lengths of 45.0 cm [18 in.] long initially
have been found to be adequate.
10.5.2 Fuse Wire—A fuse wire, connecting the ends of
opposing electrodes tips, is used to initiate the arc. This wire is
consumed during the test; therefore, its mass shall be very
small to reduce any effects on the testing. The fuse wire shall
be a copper wire with a diameter not greater than 0.5 mm
[0.02 in.].
10.5.3 Structural Cage Arrangement—The structural cage
arrangement shall be made of conductive tubes (for example,
metallic tubes such as aluminum or steel). The diameter of the
cage shall be between 2.0 m and 2.5 m. The height of the cage
shall be at least 3 m.
10.6 Electric Supply—The electric supply should be suffi-
cient to allow for the discharge of an electric arc with a gap of
up to 305 mm [12 in.] with alternating arc current of 8000 A
and with arc duration from 3 cycles (0.05 s) up to at least 90
cycles (1.5 s) (from a 60 Hz supply). The X/R ratio of the test
circuit shall be such that the test current contains a DC
component resulting in the first peak of the test current having
a magnitude of 2.3 6 0.1 times the symmetrical RMS value.
10.7 Test Circuit Control—The make switch shall be ca-
pable of point on wave closing within 60.5 ms from test to test
such that the closing angle will produce maximum asymmetri-
cal current with an X/R ratio of the test circuit as stated in 10.5.
The arc current, duration, and voltage shall be measured. The
FIG. 5 Mannequin Head with Monitor Sensors
arc current, duration, voltage, and energy shall be displayed in
graph form and stored in digital format.
TABLE 4 Position of Monitor Sensors Depending on Expected
Incident Energy
10.8 Data Acquisition System—The system shall be capable
Monitor Sensor Position Monitor Sensor Position
of recording voltage, current, and sufficient calorimeter outputs
1 2
as required by the test.
2 2
Incident energy on eyes 0 to 55 cal ⁄cm Over 40 cal/cm $
10.8.1 The temperature waveform data (calorimeter out-
and mouth calorimeters [230 J/cm] [167.4 J/cm]
puts) shall be acquired at a minimum sampling rate of 100
Distance D1, center of 340 mm ± 5 mm 410 mm ± 5 mm
samples per second per calorimeter. The acquisition system
electrode to monitor
including noise filtering shall have a frequency response of at
sensor
least 20 Hz [-3 dB]. The acquisition system shall be able to
Angle between 40º ± 5º 40º ± 5º
record temperatures to 500 °C. The temperature shall be
perpendicular line to
reported with 3 significant digits and have an accuracy of at
center of mouth
calorimeter and monitor
least 61 °C. (This does not include the accuracy of the
sensor surface
calorimeter).
NOTE 5—A minimum acquisition rate and frequency response of the
calorimeters is necessary to avoid introducing signal distortion and time
10.4.2 Only calorimetry data from heads that are viewed
shift into the waveform. synchronize the temperature curves with time
zero (t ). A sampling rate of 100 Hz provides a data point at 10 ms
from the front shall be used (a minimum 50 % view of the
intervals and a minimum 20 Hz bandwidth (corresponds to a 10 % to 90 %
facial area is required) to record subjective data during the test.
rise time of 17.5 ms) has been determined to be sufficient. The response
When one video camera is used to view the testing, it shall be
of the entire acquisition system can be checked by placing a sinusoidal
placed so that the front of two of the heads can be viewed. A
signal at the thermocouple input and analyzing the system response.
single head which is viewed from the rear may be removed to
NOTE 6—The response of the sensors during a calibration test can be
facilitate viewing. checked by examining the curve of each calorimeter and locating the
F2178/F2178M − 23a
beginning of the rising temperature region. The first data points of
12.2 Test specimens shall be mounted as they are normally
temperature rise on the sensor calorimeters should occur within 30 ms of
intended to be worn. If the position of the product is adjustable
the arc current initiation.
(such as faceshields with adjustable headgear), some tests shall
10.8.2 The waveform recorders for current and voltage data
be done in the fully in and fully out position to determine
shall be acquired at a minimum rate of 2000 samples per
which provides the lowest thermal protection. The actual
second and a frequency response of 200 Hz. The current and
distance of the shield/visor to the center line of the electrode
voltage acquisition system shall have an accuracy of at least
shall be measured and reported.
3 %.
12.2.1 Generally, the most extended position (shield furthest
10.8.3 All the waveform recorders for measuring the arc
away from the face) is more severe on the shield and allows for
current, voltage and calorimeter signals shall be synchronized
more thermal energy to go around the shield and yields the
to ensure the real time relationship between the waveforms is
lower amount of protection.
maintained and no time shift is introduced in the recorded
12.3 The thickness of the protective lens material shall be
signals.
measured with accuracy of 0.1 mm.
10.8.4 The arc initiation time (t ) corresponds to the start of
12.4 Laundering of the fabric material for hoods and bala-
the arc, and shall be reliably determined from the electrical
clavas is not required prior to testing.
signal of the arc current.
12.5 The fabric weight as tested (if applicable) for each
10.9 Data Acquisition System Protection—Due to the nature
layer shall be measured using die cut samples.
of this type of testing, the use of isolating devices on the
calorimeter outputs to protect the acquisition system is recom-
12.6 Before arc testing, the specimens shall be maintained
mended.
in laboratory conditions having a temperature between 18 °C
and 28 °C and the relative humidity between 45 % and 75 %
11. Hazards
for at least 24 h.
11.1 The test apparatus discharges large amounts of energy.
13. Calibration and Standardization
In addition, the electric arc produces very intense light. Care
shall be taken to protect personnel working in the area.
13.1 Calorimeter Calibration Check—After assembly, the
Workers shall be behind protective barriers or at a safe distance
monitor sensors and head sensors shall be checked to verify
to prevent electrocution and contact with molten metal. Work-
proper operation. The calorimeter shall be exposed to fixed
ers wishing to directly view the test shall don the appropriate
radiant heat source for 30 s while recording the output signal.
eye protection. If the test is conducted indoors, there shall be a
The temperature rise response from each calorimeter is plotted
method to ventilate the area to carry away combustion
and compared to the average. Any calorimeter having an
products, smoke, and fumes. Air currents can disturb the arc
abnormal response shall be suspected of faulty connections and
reducing the heat flux at the surface of any of the calorimeters.
shall be replaced or repaired.
The test apparatus shall be shielded by non-combustible
13.2 Another method to effectively check the response of
materials suitable for the test area. Outdoor tests shall be
each calorimeter against an average of other sensors or a
conducted in a manner appropriate to prevent exposure of the
reference calorimeter is acceptable.
test specimen to moisture and wind (the elements). The leads to
the test apparatus shall be positioned to prevent blowout of the 13.3 Each monitor sensor shall be positioned perpendicular
electric arc. The test apparatus shall be insulated from ground to the radius drawn from the center line of the electrodes to the
for the appropriate test voltage. center plane of the four-sensor head. The angle α between the
radius drawn to the center of each monitor sensor and the
11.2 The test apparatus, electrodes, and calorimeter assem-
radius drawn to the center line of the mannequin head face and
blies become hot during testing. Use protective gloves when
mouth sensor surfaces shall be 35° -0° /+ 5°, and it shall be
handling these hot objects.
possible to position each monitor sensor at the distances
11.3 Use care when the specimen ignites or releases com-
340 mm 6 5 mm or 410 mm 6 5 mm from the center line of
bustible gases. An appropriate fire extinguisher should be
the arc electrodes. Table 4 gives the distance D that has been
readily available. Ensure the materials are fully extinguished.
found to be practical, thus shall be selected for different
11.4 Immediately after each test, the electric supply shall be incident energy exposures.
13.3.1 For testing at higher incident energy ranges and for
shut off from the test apparatus and all other laboratory
equipment used to generate the arc, and the apparatus and other research, laboratories have found that allowance to adjust the
monitor sensor distance from 200 mm to 600 mm is desirable.
laboratory equipment shall be isolated and grounded. After
data acquisition has been completed, appropriate methods shall 13.3.2 The actual distance of each monitor sensor shall be
measured to a precision of 62 mm and the distance used for
be used to ventilate the test area before personnel entry. No one
the incident energy calculations.
shall enter the test area prior to exhausting all smoke and fumes
13.3.3 Examples of arrangement of six monitor sensors are
without the appropriate personal protection.
shown in Fig. 3.
12. Sampling and Specimen Preparation
13.4 Arc Exposure Calibration—Prior to each calibration,
12.1 Test specimens for four-sensor head test shall be position the electrodes of the test apparatus to produce a
representative of the product, as it will be sold. 30.5 cm [12 in.] gap. The face of the monitor sensors shall be
F2178/F2178M − 23a
parallel and normal to the center line of the electrodes. The sensors shall be cooled with a jet of air or by contact with a
midpoint of the electrode gap shall be at the same elevation as cold surface. If water is used to cool the sensors, be certain not
the center point of the monitor sensors (see Fig. 5). Connect the to over-wet the insulating material around the calorimeter as
fuse wire to the end of one electrode by making several wraps this can affect subsequent readings.
and twists and then to the end of the other electrode by the
14.2 Surface Reconditioning—While the sensor is hot, wipe
same method. The fuse wire shall be pulled tight and the excess
the sensor face immediately after each test to remove any
trimmed. Adjust the test controller to produce the desired arc
decomposition products that condense and could be a source of
current and duration.
future measurement error. If a deposit collects and appears to
13.5 Apparatus Calibration for the Four-Sensor Head and
be thicker than a thin layer of paint or the surface appears
Monitor Sensors—Position each four-sensor head so that the
irregular, the sensor surface requires reconditioning. Carefully
surface of each head is 30.5 cm [12 in.] from, parallel and
clean the cooled sensor with acetone or petroleum solvent,
normal to, the center line of the electrodes.
making certain to follow safe handling practices. Repaint the
13.5.1 Set the symmetrical arc exposure current to 8000 A
surface as noted in 10.3.4. Perform an arc exposure to cure the
6 500 A and the arc duration at 10 cycles [0.167 s].
paint and check calibration according to 13.3 after resurfacing
13.5.2 Discharge the arc.
the sensors.
13.5.3 Calculate the incident energy following the proce-
14.3 Sensor Care—The sensors shall be kept dry. For
dure in 15.9.
outdoor tests, the mannequin heads and monitor sensors shall
13.5.4 Compare the highest sensor reading and the average
be covered during long periods between tests to prevent excess
value obtained for all sensors (excluding the chin sensor), for
temperature rise resulting from exposure to the sun. Due to the
example, with the theoretical result of 10.1 cal/cm
destructive nature of the electric arc, the mannequin and head
[42.26 J ⁄cm ] for the calibration exposure of 8 kA for 0.167 s.
should be covered with the same paint as the sensors. The
Compare the total heat value determined by the sensors to the
heads should be re-coated periodically to reduce mannequin
value shown.
deterioration.
13.5.5 The average total heat calculated for the sensors shall
be at least 60 % of the value determined by calculation or that
15. Procedures for Determining the Arc Rating
shown. The highest measured total heat of any one sensor shall
be within 10 % of the calculated value. If these values are not 15.1 One of two procedures may be used for determining an
obtained, inspect the test setup and correct any possible arc rating by this standard.
problems that could produce less than desired results.
15.1.1 Devices such as spectacles, goggles or shields for eye
13.5.6 An arc exposure calibration test should be conducted
or face protection not having a fabric component shall follow
at the desired test level after each adjustment, and prior to the
Procedure A. See example flow chart in Fig. 6.
start and end of each day’s testing and after any equipment
15.1.2 System including goggles or shields in combination
adjustment or failure.
with a fabric component such as a hood, bib or balaclava shall
13.5.7 The arc generated in the testing apparatus may not
follow Procedure A or B. Procedure B may only be followed to
follow a path that is equidistant from each sensor and can result
establish performance verification once the protective level of
in a variation in measured values. To be considered calibrated,
the fabric system is known. See example flow chart in Fig. 7.
the highest total heat measured from any single sensor from a
15.2 Description of Procedure A—Procedure A is the itera-
10 cycle [0.167 s], 8000 A fault current shall not exceed
2 2 tive test procedure to determine the Arc Rating requiring
11 cal ⁄cm [46.1 J ⁄cm ] and the average total heat measured
2 minimum 20 data points and logistic regression analysis.
for all sensors in the apparatus shall be at least 6 cal ⁄cm
15.2.1 When a fabric componen
...