NBSIR 77-1222

Reproducibility of the Radiant

Panel Test Method (ASTM E

162-67) Using Polyurethane

Foam, Neoprene, and Hardboard

Specimens

T. G. Lee

Center for Fire Research

Institute for Applied Technology

National Bureau of Standards

Washington, D.C. 20234

March 1977

Final Report

U. S. DEPARTMENT OF COMMERCE

NATIONAL BUREAU OF STANDARDS

NBSIR 77-1222

REPRODUCIBILITY OF THE RADIANT

PANEL TEST METHOD (ASTM E

162-67) USING POLYURETHANE

FOAM, NEOPRENE, AND HARDBOARD

SPECIMENS

T. G. Lee

Center for Fire Research

Institute for Applied Technology

National Bureau of Standards

Washington, D C. 20234

March 1977

Final Report

U S. DEPARTMENT OF COMMERCE. Juanita M. Kreps, Secretary

Dr. Betsy Ancker- Johnson, Assistant Secretary for Science and Technology

NATIONAL BUREAU OF STANDARDS, Ernest Ambler, Acting Director

CONTENTS

Page

LIST OF FIGURES iv

LIST OF TABLES iv

Abstract 1

1. INTRODUCTION 1

2. PARTICIPANTS 2

3. TESTING PROCEDURES . 3

3.1. Standard Method. . 3

3.2. Modification of Testing Procedures 4

4. TEST MATERIALS 5

5. RESULTS 7

5.1. Survey of Operating Characteristics 7

5.2. Test Results 7

6. DISCUSSION 11

6.1. Variability and Source of Errors ...... 11

6.2. Effect of Preheating Urethane 22

6.3. Rank Ordering of Laboratories 22

6.4. Effect of Procedure Modifications 23

6.5. Analysis of Data 23

7. SUMMARY AND CONCLUSIONS 25

8. ACKNOWLEDGMENTS 26

9. REFERENCES 26

APPENDIX A. DETAILS ON TEST APPARATUS AND PROCEDURE

MODIFICATIONS OF THE RADIANT PANEL METHOD 28

APPENDIX B. SAMPLE CALCULATIONS FOR HEAT INPUT RATE

CORRECTION USED IN CALIBRATION OF

RADIANT PANEL STACK THERMOCOUPLES .... 31

APPENDIX Bl. SI CONVERSION UNITS .... 33

APPENDIX C. DEFINITION OF TERMS USED IN THE STATISTICAL

CALCULATION 34

iii
LIST OF FIGURES

Page

Figure 1. Construction and Location of the Modified

Pilot Ignitor 6

Figure 2. Data Sheet of Lab 0 for Hardboard A ... . 14

Figure 3. Plots of Flame Fronts of Hardboard A by

Lab 0 15

Figure 4. Data Sheet of Lab E for Neoprene C. ... . 16

Figure 5. Plots of Flame Fronts of Neoprene C by

Lab E 17

Figure 6. Data Sheet of Lab I for Polyurethane B. . . 18

Figure 7. Plots of Flame Front of Polyurethane B

by Lab I 19

Figure 8. Correlation Between Q and 1/3 for All Labs. 20

Figure 9. Mean I of Each Lab versus Mean I . for

All LaBs S 24

LIST OF TABLES

Table 1. Calibration and Operating Conditions for

Participating Laboratories 8

Table 2. Test Results for Each Specimen and

Laboratory 9

Table 3. Effect of Preheating on Flame-Spread Index

of Urethane Foam B 12

Table 4. Statistical Results 13

IV
REPRODUCIBILITY OF THE RADIANT PANEL TEST METHOD

(ASTM E 162-67) USNG POLYURETHANE FOAM,

NEOPRENE, AND HARDBOARD SPECIMENS

T. G. Lee

Abstract

Interlaboratory evaluation of the Radiant

Panel Method (ASTM E 162-67) for flame spread

testing of two flexible foam and one hardboard

specimens was made. Results obtained by 13

laboratories, based on 4 replicate tests, showed

that the between-lab coefficient of variation on

the flame-spread index (I

g

) was 21% for Hardboard

A, 35% for Urethane B and 45% for Neoprene C.

The within-lab coefficient of variation for the

Hardboard was 9.9%. The higher variability of

the results for the foam materials was caused by

the rapid melting of the Urethane B and unstable

flame front of the Neoprene C specimens during the

tests. An important source of error for some laboratories was in the determination of 3, the calibration constants, and the inappropriate use of

base stack temperature correction. Statistics on

the reproducibility of the flame-spread factor (F )

,

heat evolution (Q) , and I are also given. A new

b

pilot burner and other molif ications of the method

were found useful.

Key words: ASTM E 162; coefficient of variation;

flame spread tests; flexible polyurethane;

hardboard; interlaboratory evaluation; neoprene;

radiant panel test; round robin; test method.

1. INTRODUCTION

Data on the reproducibility of a standard test method

for various types of specimens are important to the testing

laboratories as well as to the material producers. These

data often form the basis for adjusting the testing procedures

and calibration techniques employed by the testing laboratories. The data on the repeatability of the method for a given type of material of known variability would also allow

the material producer to determine whether its test results

reflect a real change of the material property or merely the

uncertainty of the method as it applies to this type of

material

.

1
Test methods and procedures are generally designed to

measure a particular material property for a limited range

of materials. Precision statements on the method based on

tests of these materials are usually included in the method

or documented in the open literature. However, if the test

method were to be used for a different type of material

only marginally compatible with the original method, new

studies including test method modification should be made to

determine the reproducibility.

The Radiant Panel Test, ASTM E 162-67 [1-3] ^ was adopted

by the American Society of Testing and Materials in 1967. It

was designed to measure surface flame spread of non-melting

or very slow-melting solid materials. However, this method

has also been used recently for testing flexible foam and

other thermoplastic materials.

To ascertain the reproducibility of the method as

practiced by major testing laboratories on the flexible foam

materials, an inter laboratory evaluation, the so-called

"round-robin" study, was made. This paper reports the results

of the pilot phase of the study suggested originally by the

Flexible Foam Flammability Task Group of the Society of

Plastic Industry (SPI). The aim of this preliminary phase

was to pinpoint and correct some of the problems, which

laboratory operators may encounter, prior to the main study

and to examine the effectiveness of the modifications introduced for testing thermoplastic foam materials.

An unpublished study in 1958 by Gross [4], based on

radiant panel tests of four acoustic tile materials by eight

laboratories, showed that the use of uncalibrated radiation

pyrometers to monitor the panel output was the primary cause

of large systematic biases observed in. the test results. The

present study used calibrated pyrometers.

Since no published study on the reproducibility of this

method is available, the results of this limited work should

be useful to the estimated 40 laboratories who are using the

method for routine testing.

2. PARTICIPANTS

This report is based on the results from all 13 laboratories which collaborated in this joint study. The laboratories are:

1 Numbers in brackets refer to the literature references

listed at the end of this paper.

2
Armstrong Cork Company (John Crawford)

E. I. duPont de Nemours and Company (R. L. Jones)

Federal Aviation Administration (Eldon Nicholas)

Lawrence Livermore Laboratory (James Gaskill)

M & T Chemical (I. Touval)

Mobay Chemical (W. J. Eicher)

National Bureau of Standards (Roland Willard)

National Research Council of Canada (P. Huot)

Olin Corporation (Margot Raetz)

Stauffer Chemical Company (Richard Cope, Jr.)

Toyad Corporation (Ralph Morford)

U. S. Bureau of Mines (Hary Verakis)

U. S. Testing Company (J.E. Fuller)

These laboratories are identified in this report by code

letters only.

3. TESTING PROCEDURES

3.1. Standard Method

The apparatus and procedures of the standard radiant

panel method have been described in detail [1-3]. Essentially,

the radiant panel consists of a cast iron frame enclosing a 30 cm wide by 46 cm high porous refractory material. The

panel is mounted in a vertical plane, and a premixed air-gas

mixture supplied from the rear is burned in intimate contact

with the refractory surface to provide a radiant heat source.

The energy output of the panel, as measured by a radiation

pyrometer, is equivalent to a blackbody temperature of 670 °C.

A stack, placed under an exhaust hood and above the test

specimen, receives the smoke and hot products of combustion.

For the test, the 15- by 46-cm specimen, backed by a sheet of asbestos millboard, was placed in a metal holder and

mounted on a supporting frame. The specimen faced and inclined

30 degrees to the radiant panel such that the specimen was

closer to the panel at the top. A pilot igniter, fed by an

air-acetylene mixture, served both to initiate flaming at

the upper edge of the test specimen and to ignite combustible

gases rising from the specimen. Observations were then made

of the progress of the flame front, the occurrence of intermittent flaming as well as the temperature rise of the stack

thermocouples. The test duration was 15 minutes or until

sustained flaming had traversed downward the entire 46-cm

length of specimen, whichever time was less.

The flame-spread index, I , was computed as the product

of the flame-spread factor, F , and the heat evolution, Q,

or:

S

3
I ( 1 ) s F Q

s

where

F

s

( 2 ) The symbols t . . . t correspond to the times in minutes

from specimen exposure until arrival of the flame front at a position 7.6 cm (3 in) , 15.2 cm (6 in) ... 38 cm (15 in)

,

respectively, along the length of the specimen. The heat of

evolution, Q is expressed as

Q = 0.1 AT/B (3)

where 0.1 is an arbitrary constant. AT is the observed maximum stack thermocouple temperature rise above ambient for the

specimen minus the maximum temperature rise observed with a

thick asbestos-cement board substituted for the specimen.

The B is a calibration constant representing the maximum

stack thermocouple temperature rise per unit heat input rate

using a calibrating diffusion-type gas burner, placed near

the top of an asbestos-cement board specimen during normal

operation of the radiant panel.

Prior to the test, all specimens and composite assemblies

were conditioned by placing them in an oven at 60 °C for a 24-hour period and then allowing them to reach moisture equilibrium (constant weight) at 23 °C and at relative humidities

of 50 + 5%.

3.2. Modification of Testing Procedures

A source of error in the use of standard test methods

is the interpretation and clear understanding of the written

procedures. Thus, a meeting of potential participants to

discuss areas of ambiguity and needed changes is always desirable prior to the testing program. Interested participants

with radiant panel facilities from 20 laboratories met to

discuss and standardize the calibration and test procedures.

Some modifications and clarifications of the published ASTM

E 162-67 standard were adopted (see appendix A) . These

included: a new pilot igniter, thermocouple cleaning methods,

aluminum foil wrapping for the non-burning surfaces of the

specimen, and the use of screening to help retain the melting

specimen in the holder during testing.

4
The new pilot burner was necessary because the original

ignitor or burner was frequently extinguished by combustion

products laden with flame inhibitor from certain types

of test specimens. The new igniter consisting of a length

of two-hole porcelain tubing and using premixed air-acetylene,

was found to be stable and immune to "flame-out." Details of

its construction, location, and flow rate are shown in

figure 1.

The thermocouple bank at the top of the stack needed

periodic cleaning to eliminate heavy soot deposits which

affected the time-constant of the thermocouples. To assure

uniformity, all laboratories agreed to clean the thermocouples

prior to each run. An air jet from pressurized tubing

inserted from the side of the stack slightly above the thermocouples may be used to expedite the cleaning operation.

To avoid excessive dripping of melted specimen and subsequent cleanup, aluminum foil was used to wrap the back and

sides of the specimen before insertion into the sample holder.

Use of the wrapper also improved the test repeatability.

Wire screen, about 25 mm mesh, placed over the entire exposed

surface of the specimen retarded the dripping and improved

test repeatability.

Other modifications and interpretations detailed in

appendix A were also adopted by the participating laboratories

for this study. With the exception of these modifications,

the tests otherwise followed closely the procedures given in

the standard method.

4. TEST MATERIALS

Three different types of specimens were used for the

preliminary study. The polyurethane and neoprene materials

selected represent two of the most common flexible foams in

use today. Hardboard, a common building material, was

included to permit comparison of a material having a welldefined flame front and considered an "ideal" specimen for

the test method. The "non-ideal" polyurethane tends to melt

and flow at flaming temperature and is complicated by a fast-moving and dif f icult-to-interpret flame front. Neoprene

on the other hand, does not melt; but it emits copious smoke

including the principal flame-inhibitor HC1 , which frequently

extinguished the pilot flame of the old pilot ignitor.

Periodic ignition and flashing at different positions of the

specimen during testing also make the flame front difficult

to follow.

Test materials were obtained from commercial sources

without special control of uniformity. Specimens were cut

5
TOP VIEW

SIDE VIEW

2- HOLE PORCELAIN TUBING

PILOT FLAME

Figure 1. Construction and Location of

the Modified Pilot Ignitor

6
from the same batch, randomized and numbered before distribution. The coefficient of variation of the density of the

two foam materials, 100 by 100 by 25 mm in size, was less

than + 3 percent based on 10 replicate measurements. Each

laboratory received four specimens of each of the three

materials, and was requested to randomize the testing by

following a random sequence supplied by NBS . The materials

were

Material

Thickness

(mm)

Measured Density

(g/cm 3

) Hardboard A 8.3 1.05

Polyurethane Foam B 25 0.06

(open cell)

Neoprene Foam C 25 0.19

(closed cell)

5 . RESULTS

5.1. Survey of Operating Characteristics

Table 1 is a compilation of the operating conditions

and calibration test results from each laboratory. The

higher (gross) heating values of the calibration fuel (see

appendix B) , determined under the temperature, pressure and

moisture conditions of measurement, and the resulting 3 are

listed. Results of the latest test on the NBS standard

reference material SRM 1002b are also given. The maximum

stack temperature rise, AT

m

, based on the average of four

runs for each of three test materials and the base temperature corrections for the asbestos-cement board, at , used

B f c in calculating the net temperature rise for the material

are included on table 1. The base temperature corrections

are a source of error to be discussed later.

Typical base stack temperature, type of gas used in the

panel and pyrometer distance to the panel are also listed in

table 1 for each laboratory.

5.2. Test Results

The reported data on flame-spread factor, F

g

; heat

evolution, Q; and flame-spread index, I s , for all the specimens and laboratories are tabulated in table 2. These

specimens were conditioned in accordance with the standard

procedure

.

7
Table

1.

Calibration

and

Operating

Conditions

for

Participating

Laboratories 8

maximum

stack

temperature

rise

for

specimen,

average

for 4

tests.

stack

temperature

rise

of

AC

board

at

time

corresponding

to

'time

of

AT

for

specimen.mc
Table 2. Test Results for Each Specimen and Laboratory

Lab. Hardboard A Urethane B Neoprene C

F

s Q I s Fs Q Is F

s Q I s

4.6 27.9 127.0 25.5 11.8 302.0 1.7* 6.5 11.0

4 .

7

25.2 119.0 34.5 11.7 401.0 2.6 5.9 16.0

B 5.1 23.8 121.0 37.7 15.9 601.0 2.7 6.1 17.0

4.8 26.5 127.0 26.2 12.5 327.0 2.3 5.8 13.0

124 408 14

4.8 28.8 138.0 36.1 13.9 507.0 5. 3 e 6.6 35.0

5.6 26.9 151.0 35.8 11.7 419.0 7.7 6.3 49.0

E 5.0 20.8 104.0 37.0 13.1 485.0 7 .

0

6.0 42.0

5.0 23.8 119.0 35.8 13.9 498.0 7.0 5.4 38.0

128 476 41

5.2 18.8 98.0 45.2 11.9 537.0 2 .

5

E 4.0 9.9

5.2 17.8 93.0 55.5 11.9 648.0 2.4 4.0 9.7

F 5.2 15.8 82.0 46.8 11.1 508.0 3.0 3.7 10.5

5.5 17.8 98.0 42.3 10.9 449.0 3.0 2.0 5.9

92 536 9

4.5 27.2 122.0 43.9 15.5 682.0 1.7 8.7 15.0

4.6 29.4 136.0 31.9 12.8 407.0 4.5 9.1 41.0

H 4.5 28.9 131.0 40.0 11.1 444.0 1.8 7.6 13.0

4.6 29.2 133.0 36 .

3

10.0 362.0 1.7 6.7 12.0

131 474 20

4 .

5

35.8 161.0 30.9 14 .

7

456.0 2.5 E 10.3 26.0

4.5 36.3 164.0 37. 8 13.2 501.0 3.5 9.3 33.0

I 4.9 40.7 199.0 40.3 11.3 454.0 7.5 10.8 81.0

4.4 36.3 158.0 39.9 13.2 529.0 3.2 8.8 28.0

171 485 42

4.6 41.1 179.0 43.3 28.9 1495.0 2.6 8.9 23.0

4.1 48.9 200.0 40.0 20.4 816.0 1.6 8.3 13.0

J 4.2 50.9 214.0 43.9 26.2 1150.0 1.6 8.3 13.0

4.3 46.3 197.0 40.9 21.6 885.0 1 .

5

7.1 11.0

197 1085 15

4.4 44.5 196.0 32 .

0

19.7 617 .

0

4.8 41.1 197 .

0

43.2 13.9 603.0

K 4.9 40.7 199.0 36.5 17.3 632.0

5.6 41.5 232.0 38.2 16.4 626.0

206 619

4 .

3

34.4 149 .

0

47.4 15.2 722.0 4.1 7.0 29.0

4 .

1

34.4 141.0 37.7 14 .

7

555.0 3.9 7.0 27.0

L 4 .

2

35 .

8

151.0 36.2 17.1 620.0 3.6 6 .

3

23.0

4.2 33.2 140.0 50.8 15.2 775.0 7.2 6.5 47.0

145 668 32

4.6 35.0 160.0 41.5 12.2 506.0 5 .

1

E 8.4 43.0

4.2 37.3 157.0 40.1 9.0 361.0 1.7 7.3 13.0

N 4.8 33.9 162.0 41.9 12.3 515.0 6.1 8.1 49.0

4 .

3

34.2 146.0 43.8 8.6 376.0 4.6 7.5 34.0

156 440 35

9
Table 2. Test Results for Each Specimen and Laboratory (cont'd)

Lab. Hardboard A Urethane B Neoprene C

F

s Q I s Fs Q I s F

s Q I s

4 . 8 31 .

0

148.0 35.6 7.5 267.0 6.0* 8.2 49.0

5.0 32.5 162 .

0

34.0 9.6 326.0 6.6 9.6 63.0

0 4.8 33.3 159.0 39.1 10.0 391.0 4 . 7 7.9 37.0

5.2 35.1 182.0 36 .

7

11.3 413.0 4 . 0 10.0 40.0

163 349 47

6.0 23.6 142.0 43.8 10.0 439.0

4* 4.3 6.4 28.0

6.6 30.7 202 .

0

44 .

2

9.3 402.0 8.6 7.2 63.0

p 6.3 28.6 181 .

0

32.1 15 .

0

481 .

0

5.8 6.4 37.0

5.5 31.5 175.0 41.6 8.6 357.0 6.1 5.7 35.0

175 420 41

5.1 27.9 141.0 33.7 11.1 373.0 5 . 8 E 8.7 51.0

6.0 29.6 177.0 30.1 15.7 407.0 6.3 12.7 80.0

Q 5.6 29.4 164.0 33.8 9.9 334.0 4.5 7.8 35.0

5.9 32.8 195.0 30 .

8

12.9 297.0 5.0 12.6 62.0

169 378 57

3.8 29.4 111.0 21.6 17.8 384.0 2.8 6.7 19.0

3.9 25.6 100.0 27. 3 9.4 257.0 2.7 4.4 12.0

S 4.2 26.7 113.0 56.6 10 .

0

566.0 3.2 5.6 18.0

4.3 29.4 125.0 22.5 21.7 488.0 1.8 6.1 11.0

112 424 15

Mean 152 520 31

10
To evaluate the influence of the conditioning procedure (24 hours at 60 °C followed by conditioning to equilibrium at 23 °C and 50 percent relative humidity) on the

flame-spread index, four laboratories performed tests on

polyurethane foam B specimens with and without the 60 °C

preheating. These results, including means and standard

deviations, are given in table 3.

One of the purposes of the interlaboratory evaluation

of the test method was to determine the degree of uncertainty

of the resultant data. Table 4 summarizes the results on

F , Q, and I in terms of the means, ranges, and the withinlaboratory and between-laboratory components of the coefficients of variation for each material (see appendix C)

.

Coefficient of variation is the ratio of the calculated

standard deviation to the mean, expressed as a percent. The

within-lab and between-lab data are given in terms of the

expected precision of a single run within a laboratory and

a single run among laboratories, respectively. The values

were derived from the analysis made separately for each material using all the reported data from the 13 laboratories.

Because of the large discrepancy in the polyurethane result

between Lab J and other labs, two sets of coefficients of

variation, including as well as excluding the Lab J urethane

data, were calculated. Appendix C defines the statistics

for calculating the data in table 4 and is based on reference

[5].

In general, repeatability (within-lab) would improve

somewhat if it were based on the mean of four replicate tests.

For a method of converting the statistical result based on

a single test to that based on the mean of n tests, also see

appendix C.

Figures 2 to 7 show typical data sheets including results

for the three materials as reported by 3 labs. They also

show procedures for calculating F and Q, and for extrapolating F from a single time-distance point observed in the

neoprene specimens.

6. DISCUSSION

6.1. Variability and Source of Errors

The 3 values among laboratories are shown in table 1.

The highest 3 was reported by Lab F and the lowest by Lab J

and K. The effect of 3 on the test results for Labs F, J,

and K is illustrated in figure 8 where the error for heat

evolution, Q appears to be systematic and directly related to

the 1/3 value. In this figure, the average Q of 4 replicate

11
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All

specimens

were

subsequently

conditioned

at

50%

relative

humidity

and

23
Table 4.

Statistical

Results

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coefficient

of

variation

are

based

ona

single

test

for

the

within

laboratory

anda

single

test

for

the

between

laboratories.

Mean

of

each

laboratory

(four

replicate

tests).

Data

in

brackets

did

not

include

Lab

J.
RADIANT PANEL MEASUREMENTS - I

Sample Code No. Teat by

/V- TV-/? 5 -/fry Tr.f No. R-6- 7-9

7T(/

Date

. AssTsted by Timm.

Ufc 0

/? - 2~ Z3L

Sample Description: H ^

D

°A R E> (3 S

^

Manufacturer

Thickness .in. Density.

Special Conditions

.lb/ft3 ,lb/ft* Moisture

or oz/yd3

RECORDED DATA

(A) Flame Spread Factor, F

# - 1 + — +

T3 T6 -T3 T9 -T6

Cl)

T12‘T9 t15”t12

(2 ) Mst. Time ! Time Reciprocal Dist 'Time Time Reciprocal

In. Mln. Difference Difference In. Min. Difference Difference

3 /.ry /• 2 V » JC t> 3

!

• t.zo / . 2 0

* ,y33

6 /. 7 v v 70 / V25 6 1.77 -07 / -775

9 T,/6 / -?-2 . SZC 9 5 OB. /./3“ ->//• 12 i’.TP 2.22 75" 12 9. 77 - 197 -7/3

r~i5 1-0? ! ?. 7/ r. 7 o 15 7.7/ i 'i /7 • . C-/ <5

MFT /

J

t MFT /o'

. Test 7 09 Sum 5 77:5 Test 7.SU Sum ^

r

7

F8 - 1.00 + 7*7o' - V -779" F„ - 1.00 + 3.9/-

9

- 7 7/9

C3) (4)

Dist. Time , Time Reciprocal Dist. ! Time 1 Time Reciprocal

In. Min. Difference Difference In. Min. i Difference Difference

3 / J? - 777 3

• /./Z / /2- ./*3

fi l.?1 . 10 / , 7Z9 6 ! / 75 . C) / A 3 7

9 7/7 J 29 .775' 9 [7 V5 / . / r . 7(7 7

12 7 C5 2:0/, 9/7 12 ; 99/ 2/3 -97,9

15 v 5? Z.B. / 15 ! + 3 . 72

'MFT, o MFT / Test 7 7< S&om f0 ' Test

L/./7c F_ 1 .00+ 7 7-/7 - V 7'j"7 « 1.00+ 7 /7Q - 5'- /7c5

s ti

(1) (2)

9TO

(3) 7^2(4)

-/VO 17 / /7Z / 79 / 7^

pL5 ^ 2.77 2o'5

/// / y2 /92 9/2

223 . 25 + ?vr 2 5'3

3/’. 77 57' 5 V 35/7

13 1C / :

c 3

Specimen Maximum Stack Temp., *c) 1 'f-' Initial Stack Temp. *C C. Temp. Rise from specimen, *C Asbestos-Cement Board Stack Temp. Rise, *C

T, Net Stack Temp Rise, *C

Q-0. 1/8 T, Heat Eva. Factor,

Note: MFT-Max. flame travel distance, in. Test-Time at MFT, min.

Figure 2. Data Sheet of Lab O for Hardboard A

14
D1s

tance

,

Inches

RADIANT PANEL MEASUREMENTS - II

(C) Flame Spread Index, I

g « F

g x Q

(D) Plots of Time vs Flame Travel

^ o

/V

V.77l'v ^97- /v/

i -/ "757 v 33 33 . / 59

x /w x 35' /y -

Average “ A* 5

Time, Minutes

(E) Comments on Nature of Burning, Melting, Flash Potential, etc., during test

'l

m. m » / 7 ( L 7V^ -fr, A \ r-* / / . i . /.1 7-/, f )<>,,. / (

J 77

7

</<-[( -? i. ? " A / v

••

.> -/' />. J -7-

/

. A i/ . “V— “ ’V /

5

Figure 3. Plots of Flame Fronts of Hardboard A

by Lab 0

15
RADIANT PANEL MEASUREMENTS - I

Sample Code No. /&t 9&. 6 _Test No. ¥.s,s,/o

Test by _VL - . 1 ^ u d*~ Assisted by co.

Sample Description:—

i. fc

. Date <03-£'5-7ft

.Time

Manufacturer

Thickness / O

By Bu/rV/fU o P

.in. Density /tf , 3> Special Conditions . / _ . or oz/ydd & 60 c /t> / <j*> 2 ?pj r . <ro -

lb/ft3 ,lb/ft2 Moisture

ot °z,y^ ' ^

RECORDED DATA

(A) Flame Spread Factor, F = 1 + \

+ —prr + z~~ + i. -~

s T3 T T

6 -T3 T9-T6 T

i2" T9 t15’t12

Dist.

in.

a)

Time 1 Time 1 Reciprocal

Min. Difference ! Difference

(2 )

£>.S2*\ 0.22

A VO*1 0.90

_ 9 _12

15

liZ-V2L

MFT 9

Test /-T

f

3 = 1.00 +

Sum ft, 2ft

ft-22 - .-*7 2.<g

(3)

Dist. 'Time In. Min.

1 3 O.&ft

Time

Difference

0.63

Reciprocal

Difference

/ S9

6 ! /.00ft 0,37 2,70

9 l/ftft 0, 03 7.72,

.12. . 15

DistrTime Time Reciprocal

In. Min .

1 Difference Difference

3 0,37* C,S7 / 73T f 6 0.33 .7,03

9 / 93 OS3 7 55

12

* *

1 15 1

1

MFT 9

Test /or Strm ^ * (0 7

Fg = 1.00 + - 73,7

(4)

Dist. Time Time Reciprocal

In . Min . Difference Difference

3 d/lb/ft &.£></ - /S&

6 /30ft 0.30 2,72

9 ]/.£>/ O.L! /,0V

12

r

1 15 L- MFT

Test ,/^T

X

4>.°!

Sum 1 3L

7,0/

MFT

Test /S~

f '^i-oo-r o.yy

Sum —- jL<2£

Specimen Maximum Stack Temp., *jO

Initial Stack Temp.

°JZ Temp. Rise from specimen, aF

Asbestos-Cement Board Stack Temp. Rise,

T, Net Stack Temp Rise, °f/- Q=0. 1/6 T, Heat Eva. Factor,

15 = l-H

(l)

J&ie.

594

( 2 ) ft?ft. 9 Co 2/ 2

°F

2°

ozL O' & L

(3).

-ft- $

(41 > tw

39L . 67

lit Sft(

Note: MFT=Max. flame travel distance, in. Test=Time at MFT, min.

ft ^ 1 J)~ 7~ 6>.S ftt ftr

Figure 4 . Data Sheet of Lab E for Neoprene C

16
Distance,

Inches

RADIANT PANEL MEASUREMENTS - II

(C) Flame Spread Index, I

g - F

g x Q (L'

• (1) Ig" ^‘3

© (2) i

3 - 7‘ 7 x -

X (3) T

b - 7,0 yr &>Q - 0(4) i3 ° Z c.

(D) Plots of Time vs Flame Travel Average

y? . „ jvz

v/

(E) Comments on Nature of Burning, Melting, Flash Potential, etc., during test ^6*0^ ~7^fc ^/-~Ve.S /. *? Alar /K*

->.S Scon. itLA/j T~<«r/? </

/ncseo'itJ ~£<=> c/ec/^jg c/ /!

Km. £ /

X *4

<T/>*g/«»at-yi. /&x< /e^1 /oca/yg^ S'J?a7/i «^A^ g ,4 ___ *Wse <T».?7‘k teoy-t .... . <4 ~Tr* X>H n ^ K <Uo ^ ~ tfo ^^e^T4- ^

^cy ' 7^-g —c^-£j- —A*<x-^Lx<£) ,

Figure 5. Plots of Flame Fronts of Neoprene C

by Lab E

17
RAPT ANT PAXFr. MFASHP.FMF.NTS - I

Sample Code No. Test No. Test by Assisted by

Sample Description: llRnHWVMfc

Le(c ; J

Date 3/ll)74

Time

Manufacturer —— —

Thickness In. Density lb/f

t

3

, lb/f

t

3 Moisture %

Special Conditions or 02/yd3

RECORDED DATA

IA) Flame Spread Factor, F = 1 + — + T3 T6 -T3 T9 -T6 T

12 -T9 T15 -T12

(1) 1Q8 (2) 8

Dist • Time Time Reciprocal Dist- ' Time Time Reciprocal

in. Min. Difference Difference In. Min

.

Difference Difference

3

!

1 .1*5

! « bt7 3

j .tS 6,b7 |- 6 .31 ! . ib i. 2S 6 ,2.5 • 10 10.00 i 9 • 4ft ' .IS 5,5lo 9 .33 ,1ft “

1 7,hi 12 _ .15 1

. Ho b/Z.5 12 • SI 7. b8 15 .84 . ift 5 Zb 15 • 72 1 . 2.1 4.7A

MFT l8i»a MFT 16 .M- Test -

Sum 25.58 Test 1.20 Sum 3ig.Ql Fs = 1.00 + 74.45 = 30.55 F s O O

r—

1

il + 3b.*3

1

u £

(3) \17 (4) 47

Dist — Time Time Reciprocal Dis t

.

‘ Time Tfme Reciprocal • In. Min

.

Difference Difference In

.

Min . Difference Difference

3 H .1 + 7.14 3 .lZ \Z - 8,33 1 6 -3ft .14 7.1 + 6 . .2ft b.25

9 .514 .10 15.0C 9 ; 51 15 7. (h I 12 .4ft • H ft.Cft 12

1

, nl .eft Vl.lt

| 15 ,61 .n 15 ; .bb . 16 3.5fc> MFT MFT 18. 1 *0. Test _-.ua.. Sum 38.7.5 Test ».»l Sum 3BR4

F_ 1.00+ = 4o.zs F e - '1 -00r 55.54 = 35,54 6 s

Specimen Maximum Stack Temp., °p

Initial Stack Temp. °p

Temp. Rise from specimen, °p

Asbestos-Cement Board Stack Temp. Rise,

T, Net Stack Temp Rise, °p

Q=O.l/0 T, Heat Eva. Factor,

-£>- 1 . 02.

Note: MFT-Max. flame travel distance,

Test=Time at MFT, min.

(1) (2) 5>bS

(3)

54S

(A)

5b5

385 385 340 5=10

1 85 170 154 175

35 35 40 40

150 1 IB *35

- -14.-1

1

-1UA.- -11.27 . 13, Z4

in.

Figure 6. Data Sheet of Lab I for Polyurethane B

18
D1s

tance

,

Inches

(vA-me)

RADIANT PANEL MEASUREMENTS - II l*i&- r

(C) Flame Spread Index, I

g = F

g x Q

(D) Plots of Time vs Flame Travel

= tjUrn X r+' l' »

mx>i x 13.2+ = 50O.U

= 40.ZSvH/Z.7 = <753, i.

= Tfl.94 x B14 - S78-8

Average = 4&4-.1

(E) Comments on Nature of Burning, Melting, Flash Potential, etc., during test L)\ame

VYlftunz ><hl (BuRut^b) Ls ro, to

u

.Wtfa... rc.'WiO KlVi

Figure 7. Plots of Flame Front of Polyurethane B by Lab I 19
Figure 8. Correlation Between Q and 1/3

for All Labs

20
runs are plotted against the 1/6 where the curves are based

on the least square fit of the data. The large deviation of

Q, at least for labs F, J and K, was affected by error in

determining 6- This seems to indicate that calibration of 6 may be the most critical source of variability in calculating

the flame-spread index among labs.

The pyrometer to panel distances shown in table 1 appear

to center around 1.27 m except for labs J (0.81 m) , S (0.91 m)

and 0 (2.49 m) . Since the distance required for viewing

depends on the type of lens and the size and location of the

aperture, distances reported by the three labs might be

correct for their type of pyrometers.

The range of the maximum temperature increases (ATm ) among the laboratories for the three materials and the corrections for the temperature rise (ATC ) of the asbestoscement board (ACB) specimen are also shown in table 1. The

temperature correction is based on the time- temperature

response of the asbestos-cement board blank. The correction

to be applied should correspond to the time at which the

maximum stack thermocouple temperature was observed during

each test. Five laboratories used the same correction value

throughout, even though the times to reach the maximum temperature were different for the different specimens. The

ratio of ATC to ATm

for Hardboard A, for example, varied from

0 to 13% among the labs.

To minimize this source of error, an average timetemperature rise curve should be drawn based on many tests

using the ACB blank specimens. The appropriate temperature

correction should then be selected from the curve to suit

each test.

Results on the SRM 1002b material appear reasonably

consistent among all of the reporting labs except for Lab P,

which has the highest F s (7.3) and lowest Q (27.1). High

F s to Q ratios were also exhibited in the other three

materials tested by Lab P. The reasons for this are not

known at present.

Data from the statistical analysis in table 4 show that

within-lab variability of both F s and Q for Hardboard A were

relatively low and comparable. On the other hand, the component of between-lab variability for both F

g

and Q were

much higher, particularly the coefficient of variation for

Q. These results are probably typical of materials with

relatively uniform burning characteristics. For the cellular plastic materials, both the within-lab and between-lab

coefficients of variation were considerably larger.

21
The largest source of variability was associated with

Neoprene C. The burning characteristic of this specimen was

such that flames repeatedly flashed down from the top of the

specimen during the early part of the test exposure. Since

the duration of the flash was less than 3 seconds it was not

considered a sustained flame front in accordance with the

method. After an exposure of 1 to 3 minutes, small cracks

began to develop between the 6 and 9 inch levels thus creating anchoring locations for the flame. Under these conditions,

a stable flame usually developed at one of the crack openings.

This time was recorded. Since this phenomenon was variable,

large within- and between-lab differences for F s of Neoprene C

resulted

.

Paragraph 8.5 of the test method standard describes a method of calculating a flame-spread factor, F s , for cases

such as the one mentioned above where flames skipped one or

two distance increments and anchored in one position without

further spread. By using the prescribed equation from the

standard, D

t = D0 + 6 . 5 £n t, where the distance (D^) is in

inches and the corresponding time (t) is in minutes, D0

corresponding to a time of 1.0 minutes can be calculated.

Based on this derived DQ , other corresponding times for

distances of 3, 6, 9 or 12 inches and F s may be determined

by the above method.

F s data on Neoprene C in table 2 identified by an "E"

were from the 5 labs using this method. Data identified by an

asterisk were derived by the author using the above equation

from the reported single time-distance values from 4 labs.

The data from the remaining 3 labs indicated that 2 or more

time-distance increments were indeed observed in each test

and therefore required only normal treatment.

6.2. Effect of Preheating Urethane

Table 3 shows that the flame-spread index values for

Urethane B were not significantly affected by preheating of

the specimens (60 °C for 24 hours) prior to conditioning.

6.3. Rank Ordering of Laboratories

Rank ordering of laboratories in terms of aggregate

flame-spread index value shows that Labs J and K ranked among

the three highest laboratories for both Hardboard A and

Urethane B, whereas Lab F ranked the lowest for Hardboard A

and Neoprene C. These three laboratories also reported

values with unusually high deviations relative to those of

others. Comparison for all the labs are illustrated in

22
figure 9 where the mean of all laboratories for a material

is plotted against the mean (four replicates) of each laboratory in log-log coordinate. The graph shows the need for labs

with consistantly high or low values to examine their procedures [7] .

6.4. Effect of Procedure Modifications

The modifications adopted by the participants in this

study were found to be satisfactory. No pilot "flameout" was

reported in any test using the new burner. The aluminum

back and side wrapping and front screening alleviate the

dripping problem. Cleaning of thermocouples after each run

was considered rather difficult even with the use of the compressed air jet. The newer commercial model of the apparatus

uses a retrievable thermocouple bank which can easily be

withdrawn from the stack for cleaning after each test.

6.5. Analysis of Data

The inter laboratory variability ranged from 21% for

Hardboard A to 45% for Neoprene C in terms of coefficient of

variation for flame-spread index. The higher variability for

Neoprene C was due in part to the difficulty of defining

the flame front and the problem of a low stack temperature

rise, which was strongly affected by even a small error

in the base temperature correction for the ACB board. It

also had a relatively low flame-spread index (mean I s = 31)

,

for which a higher coefficient of variation may be expected.

Table 2 shows that the magnitude of I s for Polyurethane

B as measured by Lab J was about twice that of the average

for all the other labs. If the urethane data of Lab J were

excluded in the analysis, the between-laboratory component of

coefficient of variation could be reduced from 26 and 35

percent to only 13 and 18 percent for Q and I s , respectively,

as shown in table 4.

The within-lab coefficient of variation of I s obtained

by 13 labs for hardboard was 9.9%. This was only somewhat

higher than the value of 5.9% (12 runs) determined by a single lab, NBS , for the standard reference material 1002b,

which was also a hardboard material having an I s value of

190 [6].

The generally higher variability of Q in the betweenlab coefficient of variations for all three materials indicates the need for better control of the parameters that

affect Q among the labs. This involves primarily the calibration constant 6 . To pinpoint the source of error from

23
MEAN

I,

OF

EACH

LAB

MEAN I s OF ALL LABS

MEAN I s OF EACH LAB VERSUS MEAN I s FOR ALL LABS

Figure 9. Mean I s of Each Lab Versus Mean I for All Labs s 24
3 , more information would be required on the gas flow measuring devices and other details of the calibration procedure

used by each lab. But to minimize this type of error in the

future, a more detailed description on instruments and procedures for determining 3 should be given in the method.

Continuous soot deposits on thermocouples during a test also

play a role in the measurement precision of Q. However,

this is difficult to correct. Automatic cleaning of the

thermocouple bank after each run should be required.

Though this method was particularly useful for tests of

materials with steady and definite flame fronts, the current

study shows that the method can also be used for slow-melting

materials with less stable flame fronts. However, higher

coefficients of variation in test results are to be expected

because of the additional uncertainty in the F

g

introduced by

the slight melting and occasional flashing experienced by

these elastomeric materials.

7. SUMMARY AND CONCLUSIONS

Based on the reported test results of 4 replicate runs

for each of 3 test materials, one reference material, and the

calibration values on 3 from 13 participating laboratories in

the radiant panel study, the following conclusions are

justified

1. The within-laboratory coefficient of variation

of the flame-spread index, I

g

for Neoprene C and

Urethane B were about 4 times and 2 times higher

than the Hardboard A specimens, respectively. The

higher variability for the flexible foams may

reasonably be attributed in part to the difficulty of reading the flame front of a melting

Urethane B and the unstable flame front of

Neoprene C specimens. The base temperature

correction errors on the low stack temperature

rise from the Neoprene C specimens also affected

the variability.

2. The between-laboratory component of coefficient of

variation of I s ranged from + 21 % for hardboard

to + 45 % for neoprene.

3. The correlation between the magnitude of the Q and

the 3 values for some labs indicate that the betweenlaboratory variation can be reduced by the use of

a more explicit procedure and technique in determining the 3 values during calibration by each

laboratory

.

25
4 . The adopted modifications such as the new pilot

burner, aluminum wrapping, and screen cover in

the test procedures for melting foam specimens,

alleviated much of the difficulty of testing

this type of specimen.

5. The flame-spread index, I s , for Urethane B was not

significantly affected by preheating the specimens to 60 °C for 24 hours prior to conditioning

of the specimen at 23 °C and 50% relative humidity.

6. In the absence of a more suitable test for flame

spread of materials that melt and drip, this method

with the stated modifications appears to be suitable

for the type of elastomeric materials represented by

the Neoprene C and the slow-melting Urethane B

specimens. Because the test results have inherently

higher coefficients of variation, additional work

needs to be done to establish the type of behavior

to be expected from these types of materials.

Judgment should be used in the application of this

test and in establishing criteria for regulatory

purposes

.

8. ACKNOWLEDGMENTS

The author wishes to thank the individuals and organizations listed on page 3, for the'ir participation in performing the. tests and making the data available. Their contributions in the discussions on the testing procedures are very

much appreciated.

9. REFERENCES

[1] Standard Method of Test for Surface Flammability of

Materials Using a Radiant Heat Energy Source, ASTM E 162-

67, Annual Book of ASTM Standards American Society for

Testing and Materials, Philadelphia, 1973, Part 14.

[2] Robertson, A. F., Surface Flammability Measurements by

the Radiant Panel Method, ASTM Special Technical Publication No. 344, American Society for Testing and

Materials, 1962.

[3] Gross, D. and Loftus, J. J. , Surface Flame Propagation

on Cellulosic Materials Exposed to Thermal Radiation,

J. Res., Nat. Bur. Stand. (U.S.), 67C3 (Eng. and Instr.)

251-258 (1963) . Gross, D., Private Communication (NBS Report 6319), 1958.

26

[ 4 ]
[ 5 ] Mandel, John, Repeatability and Reproducibility, Matl.

Res. and Stand. (ASTM) Vol. 11, No. 8 (1971).

[6] National Bureau of Standard SRM 1002b certificate.

[7] Youden, W. J. , Graphical Diagnosis of Inter laboratory

Test Results, Precision Measurement and CalibrationStatistical Concept and Procedures, Nat. Bur. Stand.

(U.S.) Special Publication 300 (1969).

27
APPENDIX A. DETAILS ON TEST APPARATUS

AND PROCEDURE MODIFICATIONS OF THE RADIANT PANEL METHOD

Radiant Panel:

1. Btu-rated gas or CP grade-methane should be used

to determine the 6-value of the panel in the calibration prior to the round robin.

2. In determining the 6-value, the higher (gross)

heating value of the gas should be used. Corrections for vapor pressure (wet gas meter) , and other

measurement parameters from standard temperature

and pressure conditions are required (see end of

appendix for sample calculation)

.

3. Align and position the pyrometer properly. The

proper position for the radiation pyrometer, when

monitoring the output of the radiant panel, is

along the normal through the center of the panel

surface, and at a distance which would allow the

pyrometer to view a central circular area 250-mm

in diameter on the panel. This position should be

determined as follows: With the panel operating

and the pyrometer sighting along the normal,

slowly insert an incombustible opaque shutter in

front of the panel from the top, the bottom and

each side, in turn. Note how far the shutter must

be inserted before the .pyrometer output reading

starts to decrease. Adjust the pyrometer

along the normal until the position is found at

which the output starts to decrease when the

shutter is 25 mm from each side and 100 mm from

the top or bottom of the panel. The pyrometer

should be fixed in this position on a sturdy mount.

4. Calibrate the pyrometer if it has not been checked

during the past 2 years. (NBS will provide this

service .

)

5. Modify pilot burner assembly and adjust the flow

rates of gases to within + 3% of the suggested

values of 0.9 s,/min for acetylene and 4.5 2,/min

for air. Figure 1 shows the construction and

location of the pilot burner which would resist

"blow-out" by flame inhibitors from the test

specimens

.

6. A typical radiant panel maintained at a blackbody

temperature of 670 °C requires a gas flow rate of

about 22 £/min for natural gas (>95% CH 4 ) and

316 2,/min for air.

28
7 . Determine the stack temperature rise from the

asbestos-cement board (ACB) with the new pilot

burner as function of time. Monitor the equilibrium base line temperature of the stack for

at least 4 minutes with the pilot flame on and in

front of the radiant panel. Then insert the blank

specimen consisting of a 6 . 4-mm thick asbestoscement board and a 13-mm thick asbestos millboard

backing in the sample holder. The temperature

rise above the base line, as a function of time

shall be used to determine the correction for the

ACB temperature rise. In normal test runs, the

pilot flame should also be on and in front of the

panel prior to sample insertion.

Specimen Preparation:

1. All specimens including the hardboard shall be

heated at 60 °C for 24 hours and then conditioned

one week (minimum) at 23 + 3 °C and 50 + 5%

relative humidity.

2. Prepare aluminum foil (0.05 mm thick) wrapping

frame to fit each specimen. Install the wrapper

on the specimen before insertion into sample

holder for testing. A solid mold, identical to the

specimen in size, should be used to form the frame

to avoid unnecessary wrinkles on the foil. Cut

off excessive foil at the frame edges of the

holder

.

3. Mount poultry netting screen (25-mm hexagonal wire

mesh, 0.8-mm diameter wire) in the specimen holder

and flush against the exposed face of the specimen

for all foam materials.

4. Use 3.2-mm thick asbestos-cement board as backing

for the foam specimens and 13-mm thick asbestos

millboard for the hardboard specimen.

5. Do not compress the flexible foam specimen while

loading it into the holder.

Recording and Thermocouple Cleaning:

1. Record stack temperature by a continuous recorder

or a multi-point recorder with 5-second or less

interval per print channel.

29
2 . Flame front is defined as the maximum advance of

flame lasting 3 seconds or more. Flaming streak

associated with melted material moving down the

middle of the specimen will be considered as a flame front. However, intermittent flashing is

not considered as a flame front unless it has

stabilized for more than 3 seconds. Timing of the

flame front arrival at the 3-inch interval lines on

the specimen should be consistent. For example, if

the arrival time is defined such that half of the

length of the interval line is traversed by the

visible flame front, the same definition should

be used for all subsequent interval lines.

3. All thermocouples in the stack should be cleaned

(free of soot deposits) prior to each test run . A compressed air jet impinging on. the thermocouple

from small nozzles in a 25-mm diameter tube inserted

from a side of the stack was found to be effective

in dispersing the soot.

Test Sequence and Data Sheet:

1. A code letter is assigned to each laboratory and

labeled with data sheets.

2. Record the required information on the data sheets

including a sample of stack temperature measurement

on recorder paper; give data on 3 calculations and

plot time-distance data on the graph papers

provided

.

30
APPENDIX B. SAMPLE CALCULATIONS FOR HEAT INPUT RATE

CORRECTION USED IN CALIBRATION OF RADIANT

PANEL STACK THERMOCOUPLES

The following examples show how the required higher or

gross heating value (HHV) , which included the heat of condensation of H 2 0 in the combustion product, may be corrected for

the difference between volumes measured under your ambient

conditions and under the standard conditions. Heating

values for fuel gases are reported in terms of the standard

temperature, T s = 60 °F* and pressure, P

s = 30.0 inch Hg and

under water saturated basis as described by ASTM D 1071. Ta and Pa are ambient temperature and pressure during the

calibration, respectively.

Assume: HHV of the Btu-rated methane = 1000 Btu/ft 3 (60

°F , 30.0 in Hg, saturated).

If the flow rate was

ambient conditions:

measured by a wet gas meter at

Temperature (water) T = 90 °F

a T = 60 ° s Pressure drop (meter) Ap ~ 1" H 2 0

~

yjj—c = 0.074" 13.6

Atm. Pressure P = 30.15" Hg

a

P = 30.00

s Gas flow rate V = V ft 3 /min

Vapor Pressure PWa

= 1 * 42 " Hg (90 °F

)

PT7 = 0.52" Hg

Ws ^ (60 ° F

)

H 2 0 in wet gas meter Density of Hg = 13.6

Correction from standard conditions to measuring conditions:

HHV = 1000 x

459.7 + i 459.7 + T

x

P + AP - P

a wa

P - P

s ws

= 1000 x

459.7 + 60

459.7 + 90 x 30.15 + 0.07 - 1.4230.00 - 0.52

= 924 Btu/ft 3

To make metric conversion in Appendix B see the SI Conversion Chart in Appendix B1

.

31
(B) If flow rate was measured by a dry meter, (AP = 1"H 2 0)

the corrected HHV will be:

, 459.7 + 60 30.15 + 0.07 - 0 UUU x 45g>7 + 90 x 30.00 - 0.52

HHV = 969 Btu/ft 3

If the calibration gas is pure methane (99.93%) the

following heating values may be used: *

997.4 Btu/ft 3

, H 2 0 saturated, at 60 °F 30.0" Hg

(wet gas meter)

1015.0 Btu/ft 3

, dry, at 60 °F, 30.0" Hg

(C) If the conditions during measurement using a rotameter

(dry) were:

T

a

00 o

0 (gas temperature)

P

a 30.15" Hg, AP = 0, the correction will be:

HHV = 1015.0 459.7 + 60 30.15X 459.7 + 80 X 30.0

= 982 Btu/ft 3

If a rotameter is used, it should be calibrated for

methane and corrected for temperature. It should not

be based on that of air. The pressure drops of the

rotameter should be included in the calibration and no

additional correction is necessary. If the rotameter

is calibrated under other (temp., pressure) conditions,

the appropriate corrections should be made.

Values from Eiseman and Potter, J. of Res., Natl. Bur.

Stand., Vol . 58, p. 213 (1957).

32
APPENDIX Bl. SI CONVERSION UNITS

In view of the present accepted engineering practice in

this country, common U.S. units of measurement have been used

throughout this report. In recognition of the position of the

United States as a signatory to the General Conference on

Weights and Measurements which gave official status to the

metric SI system of units in 1960, we assist the readers

interested in making use of the coherent system of SI units

by giving conversion factors applicable to the U.S. units

used in this report.

Length

1 in = 0.0254 meter

1 ft = 0.3048 meter

Volume

1 ft 3 - 0.0283 m 3

Mass

1 lb - 0.4536 kilogram

Density

1 pc f (lb/ft 3) = 0.0160 g/cm 3

Temperature

Temperature in °F = 9/5 (temperature in °C) + 32 °F

Energy

1 Btu = 1054.6 joules

Power

1 Btu/s = 1054.6 watts

33
NBS-1 14A (REV. 7-73)

U.S. DEPT. OF COMM. BIBLIOGRAPHIC DATA

SHEET

1. PUBLICATION OK REPORT NO. NBSIR 77-1222

2. Gov't Accession

No.

3. Recipient’s Accession No.

4. TITLE AND SUBTITLE 5. Publication Date Reproducibility of the Radiant Panel Test Method

(ASTM E 162-67) Using Polyurethane Foam,

Neoprene and Hardboard Specimens

7. A UTHOR(S)

T. G. Lee

9. PERFORMING ORGANIZATION NAME AND ADDRESS

NATIONAL BUREAU OF STANDARDS

DEPARTMENT OF COMMERCE

WASHINGTON, D.C. 20234

12. Sponsoring Organization Name and Complete Address (Street, City, State, ZIP)

Same as No. 9

March 1977

6. Performing Organization Code

8 . Performing Organ. Report No.

10. Project/Task/Work Unit No. 491 5678

11. Contract/Grant No.

13. Type of Report & Period Covered

Final Report

14. Sponsoring Agency Code

15. SUPPLEMENTARY NOTES

16. ABSTRACT (A 200-word or less factual summary of most significant information. If document includes a significant

bibliography or literature survey, mention it here.) Interlaboratory evaluation of the Radiant Panel Method (ASTM E 162-67)

for flame spread testing of two flexible foam and one hardboard specimens

was made. Results obtained by 13 laboratories based on 4 replicate tests,

showed that the between-lab coefficient of variation on the flame-spread

index (I

g

) was 21% for Hardboard A, 35% for Urethane B and 45% for Neoprene

C. The within-lab coefficient of variation for the Hardboard was 9.9%. The

higher variability of results for the foam materials was caused by the

rapid melting of the Urethane B and unstable flame front of the Neoprene

C specimens during the tests. An important source of error for some laboratories was in the determination of B, the calibration constants, and

the inappropriate use of base stack temperature correction. Statistics

on the reproducibility of the flame-spread factor (F ), heat evolution (Q)

and I are also given. A new pilot burner and other modifications of the

method were found useful.

17. KEY WORDS (six to twelve entries; alphabetical order; capitalize only the first letter of the first key word unless a proper name; separated by semicolons) ASTM E 162; coefficient of variation; flame spread tests;

flexible polyurethane; hardboard; interlaboratory evaluation; neoprene;

radiant panel test; round robin; test method.

18. AVAILABILITY QT Unlimited

_ For Official Distribution. Do Not Release to NTIS

_ ^ Order From Sup. of Doc., U.S. Government Printing Office Washington, D.C. 20402, SD Cat. No. CH

lx] Order From National Technical Information Service (NTIS)

Springfield, Virginia 22151

19. SECURITY CLASS 21. NO. OF PAGES

(THIS REPORT)

UNCLASSIFIED 39

20. SECURITY CLASS 22. Price (THIS PAGE)

UNCLASSIFIED $4.00

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