A11107 310757

NBSIR 84-2890

National Voluntary Laboratory

Accreditation Program

Proficiency Testing for Thermal

Insulation Materials Laboratory

Accreditation Program

Round 9 - August 1983

U.S. DEPARTMENT OF COMMERCE

National Bureau of Standards

Office of Product Standards Policy

Gaithersburg, Maryland 20899

May 1984

—QC'

U.S DEPARTMENT OF COMMERCE

NATIONAL BUREAU OF STANDARDS

national bureau

OF STANDARDS

LIBRARY Ct^c.

NBSIR 84-2890

NATIONAL VOLUNTARY LABORATORY

ACCREDITATION PROGRAM

PROFICIENCY TESTING FOR THERMAL

INSULATION MATERIALS LABORATORY

ACCREDITATION PROGRAM

ROUND 9 - AUGUST 1983

. U

Jeffrey Horlick

U.S. DEPARTMENT OF COMMERCE

National Bureau of Standards

Office of Product Standards Policy

Gaithersburg, Maryland 20899

May 1984

U.S. DEPARTMENT OF COMMERCE, Malcolm Baldrige, Secretary

NATIONAL BUREAU OF STANDARDS, Errwst Ambler. Director

NATIONAL VOLUNTARY LABORATORY ACCREDITATION PROGRAM

PROFICIENCY TESTING

FOR

THERMAL INSULATION MATERIALS LABORATORY ACCREDITATION PROGRAM

ROUND 9 - AUGUST 1983

Jeffrey Horlick

National Bureau of Standards

Washington, DC 20234

Abstract

The National Voluntary Laboratory Accreditation Program (NVLAP) is a federal program which accredits testing laboratories satisfying

published criteria. One Laboratory Accreditation Program (LAP)

accredits laboratories for thermal insulation materials test

methods. Participation in proficiency testing is required for

certain test methods including: settled density, smoldering

combustion, surface flammability, and thermal conductivity.

Analyses and summaries of the test data returned by 30 laboratories

for these methods for Insulation LAP Proficiency Testing Round 9 are reported.

A description of NVLAP proficiency testing and how it fits into the

laboratory evaluation process is given.

Key words: accreditation; fire tests; laboratory evaluation;

laboratory performance; proficiency testing; settled density;

smoldering combustion; surface flammability; thermal conductivity;

thermal insulation

1. INTRODUCTION

The National Voluntary Laboratory Accreditation Program (NVLAP) provides a proficiency testing program for laboratories accredited under the Thermal

Insulation Materials Laboratory Accreditation Program (Insulation LAP).

Participation in the proficiency testing program is required for thermal

conductivity, settled density, surface flammability, and smoldering combustion

test methods.

This report presents the analyses of test data returned by 30 laboratories for

Round 9 of Insulation LAP proficiency testing. The details and results o

f Rounds 1 through 8 have been presented in previous reports [1]*. A descriptor

of how proficiency testing fits into the NVLAP accreditation process is giv-n

in Appendix A. Additional information about NVLAP proficiency testing can hr* found in references [2] and [3].

* Numbers in brackets refer to the literature references listed at the er 1 this report.

1
Three different materials were used for testing in Round 9. These sample

materials are described in Table 1.

Table 2 is a description of statistical terms used in the presentation of the

results of Round 9 analyses presented in Table 3. At the end of Table 3 are specific notes, where applicable, concerning each test method. Outlying

laboratory results were identified using methods in American Society for

Testing and Materials (ASTM) E178, Standard Practice for Dealing with Outlying

Observations. Outliers are not included in the Group Mean and other

statistical calculations shown in the Table. These outliers may also be

missing from some of the diagrams because they are beyond the scale selected

for displaying the data. Participants are urged to locate their results on the

individual diagrams for the test methods in which they report data.

2. ANALYSES OF PROFICIENCY TEST DATA

2.1 Apparent Thermal Conductivity

Proficiency testing was conducted using two different test methods for

apparent thermal conductivity; ASTM C177 (Guarded Hot Plate) [4] and ASTM C518

(Heat Flow Meter) [5].

In Round 9, each test specimen consisted of the 4 pound per cubic foot (64

kg/cubic meter), foil-faced, 1-inch (2.54 cm) thick fiberglass boards,

previously used by participants for testing in Round 6 and Round 8, stacked in

pairs to form a 2-inch (5.08 cm) thickness. These materials were to be

retained by each laboratory. The foil faces were on the outside of the stack

facing the cold plate, hot plate, and metering device(s). Laboratories cut

thermal breaks in those foil faces in contact with the metering device(s) when

appropriate. The thermal break is created by removing a small section of foil

around the perimeter defined by the apparatus meter area.

The group results, shown in Table 3, were very uniform as can be seen by the

small percent coefficients of variation (% C.V.). The range of the laboratory

results was 4.1% of the group mean for the ASTM C177 test and 5.3% of the

group mean for the ASTM C518 test. The spread of results is due to a combination of laboratory effects and variability of the test material. Since

there is no data for the variability of the individual test specimens, no attempt was made to separate the effects.

Table 4 gives a summary of the test data for Rounds 6, 8, and 9. An analysis

was made using the data for all three rounds from laboratories that 1)

participated in all three rounds, and 2) used the original material for all

three rounds. The second condition was set because some of the laboratories

did not retain one or both sets of material and were sent replacements. The

laboratory data meeting the conditions were put through the same computer

program as the individual rounds and outliers were removed from the Group

Means. The results are called "combined" in Table 4.

2
The percent coefficients of variation for the combined data for both test

methods are approximately 1 . 1 %. The range of the laboratory results was 2.8%

for the C177 test and 4.3% for the C518 test.

The units for apparent thermal conductivity (k a pp) can be expressed as Btu/(lvft 2 * (°F/in)) or W/(m2* (K/m)

. The latter term may be abbreviated as W/(m*K) as noted in ASTM E380 [6]. The reason for expressing the units the

first way is that it is indicative of the property being measured. Thermal

conductivity is the heat flow rate (Btu/h or W) through a unit area (ft^ or m 2) when the temperature gradient is unity (°F/in or K/m).

2.2 Settled Density

The settled density test is contained in the Interim Safety Standard for

Cellulose Insulation [7]. This test method replaces the earlier Federal

Specification HH-I-515D [8].

The group results for the settled density test are shown in Table 3. Table 5 gives a summary of the results for settled density for Rounds 3 through 9. The

percent coefficient of variation has remained relatively stable since Round 5.

Table 6 gives the percent deviation of each laboratory's results for the seven

rounds. Some of the laboratories reported making changes in their procedures

and equipment following Round 7.

It has been suggested that differences in sample container height is a source

of between-laboratory bias. This was seen with one of the NVLAP laboratories.

Short containers tend to give high results. In the next round of proficiency

testing, laboratories will be asked to report the size, shape, and material of

their containers.

Another possible source of between-laboratory bias may be the age and

condition of the shaker. It has been suggested that the shake pattern and

intensity may change with age (machine use time). A simple method for looking

at the shaker patterns is as follows: Fasten a pen firmly to the shaker table.

Place a sheet of paper in a clipboard. While the shaker is operating, draw the

paper past the pen, making firm contact with it and note the period of time

that the pen is touching the paper. By noting the distances from + peak to - peak vertically, an average amplitude can be calculated. The frequency or rate

can be calculated by counting the number of cycles drawn and dividing by the

time that the pen touched the paper.

Other variables include voltage settings to the blower and condition of the

cellulosic material as it is being fed into the inlet tube.

2.3 Surface Burning Characteristics

2.3.1 Critical Radiant Flux Test

The critical radiant flux test method (radiant panel) is contained in th** Interim Safety Standard for Cellulose Insulation [9] which replaces the

earlier Federal Specification HH-I-515D [8].

3
The group results for this test are given in Table 3. The percent coefficient

of variation for this round was 14%. Some of the laboratories reported that

the test material burned to the limit of their test specimen container. The

group statistics therefore, must be compared with caution to other rounds.

Three laboratories reported that one or more specimens burned to the limit.

Original photographs of the burned specimens were requested from the

laboratories. These photographs were reviewed as part of the evaluation of the

data. No unusual burn-front patterns were seen. It was noted however, that the

specimen surfaces for the outlying laboratory were unusually smooth. The

photographs have been very useful in evaluating the laboratory data.

A comparison of the radiant energy flux profiles reported by participants has

been made. The results of this comparison make it possible to identify flux

profiles which differ from the expected curve shape. Differences in curve

shape seem to come from two very different sources; the measurement of the

flux at the dummy specimen and the drawing of the curve through the points on the profile chart. Although the differences are small, they may be significant

because the critical radiant flux for a specimen is determined from the

profile curve.

A computer curve fitting method [10] has been used to draw the flux profile

curve for each laboratory. The fitting algorithm forces a smooth curve to go

through all of the data points.

Figure 1 shows the Standard Radiant Heat Energy Flux Profile curve produced by

the computer program. The data points are the same as those that were used to

produce the curve shown in Figure 8 of the Interim Safety Standard for

Cellulose Insulation, 16 CFR Part 1209. The x's above and below the curve mark

the limits on the flux profile as specified in paragraph 1209.6 section

(e)(3).

Figure 2 shows the flux profiles reported by three participating laboratories.

Curve A, has the expected shape for a good flux profile. Curve B, from a second laboratory, is close to the expected shape. The left end of the curve may be too straight and there is a small wave in the middle. Curve C, from the

third laboratory, has an unexpected shape. The extra waviness indicates that

something is different about the flux profile. This may be due to errors in

measurement, non-uniformity of the gas panel, or some other effect. This

laboratory should determine the causes of the different shape. It should be

noted that each of the three flux profiles meets the test method requirement

at 20, 40, and 60 centimeters.

Small variations in the measurement of the flux at each point may lead to

slight irregularities in the computer-plotted curve. It has not yet been

determined at what level these irregularities indicate a laboratory problem

that requires attention.

2.3.2 Flame Spread Index Test

The flame spread index is measured using ASTM E84 tunnel test method [11]. The

group results for this test are given in Table 3.

4
The test was conducted using a urethane foam board material. All eight

reporting laboratories were included in the Group Mean with a percent

coefficient of variation of 13%. This % C.V. was the lowest of Rounds 3

through 9. The flame spread classification for each of the 6 rounds (there was

no testing in Round 8) was in the range 20 to 30.

2.4 Smoldering Combustion

The smoldering combustion test method is contained in the Interim Safety

Standard for Cellulose Insulation [12] which replaces the earlier Federal

Specification HH-I-515D [8].

A specially prepared loose fill type material was used for Round 9 testing.

The group results are given in Table 3. The weight loss due to smoldering

combustion was approximately 53%. The percent coefficient of variation was

20%.

The Interim Safety Standard established a maximum weight loss of 15 percent

for material with acceptable smoldering resistance [12, 13]. Due to the nature

of the test, a cellulosic loose fill material which passes the standard

typically exhibits a weight loss of about 1 or 2 percent. Materials that fail

typically exhibit a weight loss in excess of 30 percent.

3. COMMENTS

NVLAP will continue to highlight test methods in future rounds. The goal is to

identify areas for improvement in laboratory practices as well as in test

methods. This effort depends on the availability of customized materials for

testing and the continued excellent cooperation of the participants.

4. REFERENCES

[1] Horlick, 0. "NBS Collaborative Reference Program for Thermal Insulation

Materials", Thermal Conductivity Report 1 NBSIR 79-1817, National Bureau

of Standards, Washington, DC (Nov. 1979)

Horlick, J., NVLAP Insulation TECH BRIEF series:

Rounds 3 & 4, November 1981

Rounds 5 & 6, September 1982

Round 7, March 1983

Round 8, May 1983

[2] Kirkpatrick, D., and Horlick, J., "Proficiency Testing: An Essential

Element of Laboratory Accreditation"; ASTM Standardization News, pp 14-

17 (Dec. 1980).

5
[3] Kirkpatrick, D., and Horlick, J., "Proficiency Testing: An Essential

Element of Laboratory Performance Evaluation and Accreditation"; American

Society for Testing and Materials Special Technical Publication 814, 128-

140 (1983).

[4] American Society for Testing and Materials C177-76, Standard Test Method

for Steady-State Thermal Transmission Properties by Means of the Guarded

Hot Plate, 1916 Race Street, Philadelphia, PA 19103.

[5] American Society for Testing and Materials C518-76, Standard Test Method

for Steady-State Thermal Transmission Properties by Means of the Heat

Flow Meter, Race Street, Philadelphia, PA 19103.

[6] American Society for Testing and Materials E380-82, Standard for Metric

Practice, 1916 Race Street, Philadelphia, PA 19103.

[7] Federal Register, 16 CFR Part 1209 - Interim Safety Standard for

Cellulose Insulation, Vol . 44, No. 131, July 6, 1979, pp. 39966-39968,

Sec. 1209.4, Test procedures for determining settled density.

[8] Federal Specification HH-I-515D, Insulation Thermal (Loose Fill for

Pneumatic or Poured Application): Cellulosic or Wood Fiber, June 15,

1978, Amendment 1, October 11, 1979.

[9] Federal Register, 16 CFR Part 1209 - Interim Safety Standard for

Cellulose Insulation, Vol. 44, No. 131, July 6, 1979, pp. 39969-39971,

Sec. 1209.6, Test procedures for critical radiant flux.

[10] Kahaner, D., Horlick, J., and Wyman W., "Mathematical Software in BASIC

-- DINT: Data Integration", to be published in IEEE Micro.

[11] American Society for Testing and Materials E84-81a, Surface Burning

Characteristics of Building Materials, Race Street, Philadelphia, PA

19103.

[12] Federal Register, 16 CFR Part 1209 - Interim Safety Standard for

Cellulose Insulation, Vol. 44, No. 131, July 6, 1979, pp. 39972-39972,

Sec. 1209.7, Test procedures for smoldering combustion.

[13] Lawson, J.R., Technical Support for the Consumer Product Safety

Commission 1979 Interim Standards for Cellulose Insulation, NBSIR 81-

2213, March 1981.

6
Table 1. Proficiency sample materials

Round 9 - August 1983

Apparent Thermal Conductivity, ASTM C177

ASTM C518

The test specimens consisted of 4 pound per cubic foot (64 kg/cubic meter),

foil-faced, 1-inch (2.54 cm) thick fiberglass boards stacked in pairs to form

a 2-inch (5.08 cm) thickness.

Settled density, 16 CFR Part 1209 (formerly HH-I-515D)

Radiant panel, 16 CFR Part 1209 (formerly HH-I-515D)

Smoldering combustion, 16 CFR Part 1209 (formerly HH-I-515D)

The test material was a batch of specially formulated cellulosic loose-fill

insulation. The level of fire retardancy was chosen to give smoldering

combustion results at the 50% weight loss level.

Surface Burning Characteristics, ASTM E84

Each laboratory received twelve pieces of rigid urethane foam 24 by 24

inches (61 by 61 cm) by two inches (5.08 cm) thick yielding 48 square feet

(4.5 square meter).

7
Table 2. Statistical terms and diagrams used in Table 3

TERMS:

GROUP MEAN - the arithmetic average of all of the laboratory results, except

those that were determined to be outliers.

SD MEANS - the standard deviation among the laboratory results making up the

Group Mean, the between laboratory standard deviation.

LABS - the number of laboratories reporting data.

LABS IN MEAN - the number of laboratories included in the Group Mean.

RANGE - the difference between the highest and lowest reported laboratory

results included in the Group Mean.

% C.V. - The percent coefficient of variation, defined as (Sd Means/Group Mean)

times 100, is a measure of the dispersion or scatter of the data.

UNITS - the unit of test in which the data is presented in the Table and on the

horizontal axis of the diagrams.

DIAGRAMS:

A simple plot of the data accompanies each analysis when such a plot is

possible. The horizontal axis for each plot is the test variable. The vertical

axis is the frequency of occurrence. Each laboratory's reported value is

represented by a dot (•) or an "X". An "X" indicates that the value was an outlier and is not included in calculating the Group Mean. The Group Mean is

indicated on the plot by a small arrow above the proper place on the horizontal

axis.

For display purposes, the plot covers a range of approximately +3 standard

deviations of the Group Mean. Laboratories whose data are outside this range

may not appear on the plot.

Notes following Table 3 explain special cases and give the outlying test

values that do not appear on the plots.

8
Table 3. Statistical Analyses of the Data

(1) Round 9 - August 1983

Apparent Thermal Conductivity, k app

ASTM Method C177-76

Sample material: Foil-faced fiberglass

Units: Btu / hr *ft2* (°F/in)

Group Mean = .2270

Sd Means = .0033

Labs =8 - Labs in Mean =7

Range = .0094

% C.V. = 1.45

(see Table 1) *

• • • • •

1 1 1 1 1 1 .22 .23 .24

(2)

Apparent Thermal Conductivity, k app

ASTM Method C518-76

Sample material: Foil-faced fiberglass (see Table 1)

Units: Btu / hr*ft2* (°F/in)

Group Mean = .2247

Sd Means = .0032

Labs = 22

Labs in Mean = 19

Range = .0120

% C.V. = 1.43

XX

r"

.21

• 1 • ••i

"T~

.22

i.23 .24

(3)

Settled Density

16 CFR Part 1209 (formerly HH-I-515D)

Sample material: Loose fill (see Table

Units: Pounds per cubic foot

Group Mean = 2.88

Sd Means = .23

Labs = 9

Labs in Mean = 9

Range = .72

% C.V. = 8.1

1)

• •• • ••• • “I 1 1 1

1 2.5 3.0 3.5

see NOTES following Table 3

9
Table 3 (continued)

(4) Critical Radiant Flux Test

16 CFR Part 1209 (formerly HH-I-515D)

Sample material: Loose fill (see Table 1)

Units: Critical radiant flux, watts/cm^

Group Mean = .12

Sd Means = .02

Labs = 9

Labs in Mean = 8

Range = .05

% C.V. = 14

O* • • n—i—i—

.12 .14

I I I I .18 .20

(5) Flame Spread Index Test

ASTM Test Method E84-81a

Sample material: Foam board (see Table 1)

Units: Flame Spread Classification

Group Mean = 25.2

Sd Means = 3.3 • • Labs = 8

• •• • • •

1 1 Labs in Mean = 8 r~ —i 1 1 1 1—|1 Range = 10.0 15 20 25 30 35

% C.V. = 13.

(6) Smoldering Combustion

16 CFR Part 1209 (formerly HH-I-515D)

Sample material: Loose fill (see Table 1)

Units: Weight loss, percent

1

Group Mean = 53.

Sd Means = 10. •

• Labs = 9 • • • • • • Labs in Mean = 8 i i i i 1 1 1 Range = 28. 20 30

% C.V. = 20.

40 50 60 70 80

see NOTES following Table 3

10
Table 3 (continued). Notes

Note on (1) Apparent Thermal Conductivity, C177:

One laboratory value not included in the Group Mean is an outlier as determined by tests in ASTM E178. It is beyond the

limits of the plot. The outlying value was 0.267.

Note on (2) Apparent Thermal Conductivity, C518:

Three laboratory values not included in the Group Mean are outliers as determined by tests in ASTM E178. The X's denote

outliers. The outlying value off the plot was 0.254.

Note on (3) Settled Density:

See Tables 5 and 6.

Note on (4) Critical Radiant Flux Test

One laboratory value not included in the Group Mean is an outlier as determined by tests in ASTM E178. It is beyond the

limits of the plot. The outlying value was 0.22.

Laboratory data indicated by an "o" contain one or more values

that are at the limit of the flux curve.

Note on (6) Smoldering Combustion:

One laboratory value not included in the Group Mean is an outlier as determined by tests in ASTM E178. It is beyond the

limits of the plot. The outlying value was 2%.

11
Table 4. Apparent thermal conductivity, summary of results for

Rounds 6, 8, and 9

ASTM Method C177 Round 6 Round 8 Round 9

Group Mean 0.2245 0.2252 0.2270

Sd Means 0.0022 0.0044 0.0033

Labs in Mean 9 8 7

ASTM Method C177 Round 6, 8, and 9 Combined

Group Mean 0.2257

Sd Means 0.0024

Labs in Mean 6

ASTM Method C518 Round 6 Round 8 Round 9

Group Mean 0.2249 0.2242 0.2247

Sd Means 0.0042 0.0027 0.0032

Labs in Mean 22 22 19

ASTM Method C518 Round 6, 8, and 9 Combi ned

Group Mean

Sd Means

Labs in Mean

0.2241

0.0025

14

For the combined analyses, laboratories were included in the Group Mean only if;

1) they participated in all three rounds, 2) they used the original materials in

all three rounds, and 3) they were not found to be outliers in the combined

analyses.

12
Table 5. Settled density, summary of statistics for

Rounds 3 through 9

Statistic Round 3 Round 4 Round 5 Round 6 Round 7 * Round 8 Round 9

(May 80)

Group Mean

(in lb/ft 3

)

2.63

Standard

Deviation of

the Means

0.32

Range 1.07

% Coefficient

of Variation

12.3

Number of Labs

Reporting

14

Number of Labs

in Group Mean

14

an 81) (Jul 81) (Nov 81)

2.74 2.64 2.14

0.32 0.22 0.18

1.11 0.72 0.64

11.6 8.2 8.4

15 14 14

15 14 13

(Jun 82) (Dec 82) (Aug 83)

3.04 3.13 2.88

0.25 0.21 0.23

0.74 0.54 0.72

8.3 6.7 8.1

12 10 9

11 9 9

* The portion of this table covering Rounds 3 through 7 was presented in a TECH

BRIEF which was sent to each laboratory in October 1982.

13
Table 6 Settled density, percent deviation of laboratory

results from group means for Rounds 3 through 9

LAB ROUND 3 (May 80)

PERCENT DEVIATION

ROUND 4 ROUND 5 ROUND 6 (Jan 81) (Jul 81) (Nov 81)ROUND 7 (Jun 82)

AVERAGE

PERCENT

DEVIATION,

ROUNDS 3-7

PERCENT DEVIATION

ROUND 8 ROUND 9 (Dec 82) (Aug 83)

A 7.6 10.6 8.3 27.6* 28.2* 16.5 26.2*

B 12.2 23.0 11.7 10.3 11.1 13.7 -1.1 5.3 c 20.5 16.1 7.6 7.5 10.8 12.5 8.9 12.0

D 2.2 5.7 16.8 9.2 8.5 5.9 -6.2

E -1.1 10.2 7.6 5.6

F 19.0 6.2 -1.9 -0.9 5.6

G 5.7 1.5 4.9 -0.5 -6.9 0.9 H -A. 9 -3.3 1.1 3.3 -3.9 -1.6 -6.4 -5.0

I 0.4 -4.7 -3.4 -0.9 -4.3 -2.6

J -6.1 -11.7 -5.7 4.7 -4.3 -4.6 -1.7 0.2

K -1.1 -13.1 -1.5 -5.1 -5.2 -4.9 -13.2

L -4.9 -7.7 -3.3 -5.3 M -16.3 -2.6 -5.3 -3.3 -4.9 -6.5 -4.0 4.2

N -12.9 -17.5 -15.5 -12.6 5.6 -10.6 10.3 8.0

0 -20.2 -10.6 -12.9 -13.1 -13.1 -14.0 -7.0 -5.2

Lab test value - Group Mean

Percent Deviation = x 100

Group Mean

* indicates laboratory used pouring method and was excluded

from the Group Mean calculation

The portion of this table covering Rounds 3 through 7 was presented in a TECH

BRIEF which was sent to each laboratory in October 1982. As a result of that

TECH BRIEF, some of the laboratories reported that they modified their equipment

or test method.

14
WATTS/cm?

1 .10

1.00

0.90

0.80

0.70

0.60

0.50

0.40

0.30

0.20

0.10

0 H 1 1 1 1 1 1 1 f- 10 20 30 40 50 60 70 80 90

DISTANCE, cm

Figure 1: Standard Radiant Heat Energy Flux Profile curve

15
Figure 2: Computer generated flux profile curve

A: Expected shape for a good flux profile.

C: Unexpected shape with extra waviness.
APPENDIX A

PROFICIENCY TESTING - AN ESSENTIAL PART OF NVLAP

NVLAP is a voluntary program which accredits laboratories for specific test

methods, not on a laboratory entity basis. Accredited laboratories participate

in proficiency testing for those methods requiring it. The test results are used by both NVLAP and the participants to monitor laboratory performance. If

proficiency testing data indicate poor laboratory performance, NVLAP may send

additional material for follow-up testing or schedule on-site monitoring

visits. Depending on the test method, the test results must be within

statistical bounds compared to the group or must be within specified accuracy

in order for the laboratory to be accredited.

NVLAP accredits and continues accreditation of individual laboratories based

on a technical evaluation of:

- information provided by the laboratory in its annual application

- periodic on-site assessments of the laboratory by technical experts

- results of periodic proficiency testing in which the laboratory

participates

NVLAP proficiency testing programs are inter laboratory testing programs in

which specially chosen samples are periodically distributed to and tested by

participating laboratories in accordance with specified test methods.

Proficiency testing is an integral part of the NVLAP accreditation process. It

is a means of assessing laboratory performance by analyzing results generated

by the laboratory in actual testing.

In addition to fulfilling NVLAP requirements, the proficiency testing program

provides the participants with a means of comparing their performance and

results with those from a group of peer laboratories. NVLAP also provides the

standards-writing community with statistical information and information about

problems encountered by users of the test methods.

Proficiency testing requirements are based on the needs and limitations of

each LAP and are described in a LAP Handbook provided to each laboratory. Not

all test methods covered by a LAP have proficiency testing requirements.

However, proficiency testing is required for test methods that are of

significant importance to the industry or to users of the laboratory

services. Proficiency testing may also be implemented in areas needing

improvement in testing technology or laboratory performance.

A NVLAP project leader coordinates proficiency testing programs for each LAP

and is responsible for:

- test sample selection and distribution

- experimental design based on the test method, number of laboratories, and

types of samples available

- preparation of testing instructions and data sheets

- statistical analyses and tabulation of test data

- preparation and distribution of reports to participating laboratories and

technical groups having direct interest in the test results.

Additional information about NVLAP is available from: National Voluntary

Laboratory Accreditation Program, National Bureau of Standards, Washington,

DC 20234, telephone (301) 921-3431.

A-l
NBS-114A (REV. 2-80

U.S. DEPT. OF COMM. 1. PUBLICATION OR 2. Performing Organ. Report No. 3. Publication Date BIBLIOGRAPHIC DATA

REPORT NO.

June 1984

SHEET (See instructions) NBSIR 84-2890

4. TITLE AND SUBTITLE

National Voluntary Laboratory Accreditation Program

Proficiency Testing for

Thermal Insulation Materials Laboratory Accreditation Pro

Round 9 - August 1983

gram

5. AUTHOR(S)

Jeffrey Horlick

6. PERFORMING ORGANIZATION (If joint or other than NBS, see instructions)

NATIONAL BUREAU OF STANDARDS

DEPARTMENT OF COMMERCE

WASHINGTON, D.C. 20234

7. Contract/Grant No.

8. Type of Report & Period Covered

Final

9. SPONSORING ORGANIZATION NAME AND COMPLETE ADDRESS (Street. City, State, ZIP

10. SUPPLEMENTARY NOTES

[321 Document describes a computer program; SF-185, FIPS Software Summary, is attached.

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

bibliography or literature survey, mention it here)

The National Voluntary Laboratory Accreditation Program (NVLAP) is a federal

program which accredits testing laboratories satisfying published criteria.

One Laboratory Accreditation Program (LAP) accredits laboratories for

thermal insulation materials test methods. Participation in proficiency

testing is required for certain test methods including: settled density,

smoldering combustion, surface flammability, and thermal conductivity.

Analyses and summaries of the test data returned by 30 laboratories for

these methods for Insulation LAP Proficiency Testing Round 9 are reported.

A description of NVLAP proficiency testing and how it fits into the

laboratory evaluation process is given.

12. KEY WORDS (S/x to twelve entries ; alphabetical order; capitalize only proper names; and separate key words by semicolons)

accreditation; fire tests; laboratory evaluation; laboratory performance;

proficiency testing; settled density; smoldering combustion; surface

flammability; thermal conductivity; thermal insulation

13. AVAILABILITY

[Xj Unlimited

| | For Official Distribution. Do Not Release to NTIS

~1 Order From Superintendent of Documents, U.S. Government Printing Office, Washington, D.C. 20402.

QL] Order From National Technical Information Service (NTIS), Springfield, VA. 22161

14. NO. OF

PRINTED PAGES

22

15. Price

$7.00

USCOMM-DC 0CU3-P80