In Search of Standard Reference Materials (SRMs) for ASTM E05 Fire Standards by. Norman Alvares & Harry Hasegawa

Transcription

1 In Search of Standard Reference Materials (SRMs) for ASTM E05 Fire Standards by Norman Alvares & Harry Hasegawa

2 First Paragraph of E-691 Tests performed on presumably identical materials in presumably identical circumstances do not, in general, yield identical results. This is attributed to unavoidable random errors inherent in every test procedure; the factors that may influence the outcome of a test cannot all be completely controlled. Further in the same paragraph the factors are identified: Many different factors (apart from random variations between supposedly identical specimens) may contribute to the variability in application of a test method, including: a. the operator, b. equipment used, c. calibration, and d. environment.

3 Bylaws ASTM Committee E05 Fire Standards 10.8 Every ASTM E05 fire test standard shall comply with the requirements of ASTM E 535, Standard Practice for Preparation of Fire- Test-Response Standards. This shall include the requirement that each fire test standard contain both a statement about precision and bias and a statement about uncertainty of measurement.

4 Survey of Inter-laboratory Studies (round robins) C Sealants and Gaskets 7 standards D Textiles 80 standards E Building Materials and Contents 67 standards F Protective Clothing 15 standards G Oxygen Index 5 standards 28 (35%) of the D standards conduced round robins and 15 (19%) contained precision and bias statements. 7 (47%) of the F standards conducted round robins and 6 (40%) had precision and bias statements. 1 (20%) of the G standards conducted a round robin and included a precision and bias statement. Out of 67 E standards, 22 (33%) conducted round robins and 14 (21%) contained precision and bias statements.

5 Fire Test Characteristics Sub- Committee Sub-Committee Name Active Standards Measured Parameters Type of Tests E05.11 Fire Resistance 7 Fire Resistance Furnace Tests E05.14 External Fire Exposure E05.15 Furnishings & Contents E05.21 Smoke & Combustion Products 2 FSR, Penetration Resistance Fire Exposure 6 HRR, Ignition Calorimeter Tests 11 Obscuration, HRR, Ignition, Mass Loss, FSR E05.22 Surface Burning 8 FSR, Ignition, Critical Flux E05.23 Combustibility 2 Mass Loss, Temperature Rise Smoke Chamber Flamespread Tube Furnace

6 4. USE TRACEABLE STANDARD REFERENCE MATERIALS Reference material uses include validation methods that help ensure accurate data from individual test runs, calibrating instruments and assessing analyst proficiency. In the United States, a NIST standard reference material is considered the gold standard for that material. NIST has more than a thousand different SRMs covering diverse technologies. 2 The results of analyses backed by NIST-traceable SRMs are widely accepted as valid. An SRM must be fit for its intended use. In all cases, maintain high quality reference materials to maximize their usable life, and when you find a good one, don t let it out of your sight. Page 28, Practice 4

7 Current Calibration & Reference Materials E 84 uses inorganic reinforced cement board and select grade red oak. E 162 uses inorganic reinforced cement board. E 906 uses methane to calibrate for heat release rate. Schneller Standard Panel for FAA. E 1354 uses methane for electronic mass flow meter calibration, specified PMMA for checking system calibration, ethanol for orifice coefficient checks. E 1623 uses either propane or methane with a sand burner. E 2058 uses acetone to determine effective heat of combustion.

8 Existing RMs The Schneller Standard Core Panel is used as a Standard Test Substrate for all OSU Heat Release and NBS Smoke Testing at Schneller since Some of the current uses are: OSU & NBS screening substrate for decorative development Incoming materials screening for Quality Assurance Vendor screening and qualification substrate. E05 Wood Deck

9 User s Guide for the Cone Calorimeter

10 NIST Certified E05 SRMs E : Surface flammability, SRM 1002c. E (NFPA ): Flooring Radiant Panel, SRM. E and E b: Cigarette ignition strength and standard cigarette for ignition resistant testing. SRM No s 1082 and E (NFPA ): Smoke density chamber. SRM 1006d; non-flaming exposure (paper). SRM 1007b; flaming exposure (plastic). Non ASTM smoke toxicity cup furnace standard; SRM 1048, University of Pittsburgh Method, SRM 1049.

11 Fire Research

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13 Certified Values and Uncertainties: A NIST certified value is a value for which NIST has the highest confidence in its accuracy and that all known or suspected sources of bias have been investigated or accounted for by NIST. Certificate Issue Date: 06 May 2008

14 Current Basis for SRM Development The NIST SRM web page outlines the criteria and bases for SRMs as follows: The certificates for NIST Standard Reference Materials (SRMs) traditionally have been in conformance with guidance criteria for the contents of certified reference material (CRM) certificates are contained in ISO Guide 31.

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20 European Standards

21 Potential SRM Candidates Thermosetting Composites, elastomeric materials, loaded phenolic resins. Inert porous materials preloaded with thermoplastic or flammable gels. Some space shuttle tile materials may be useful as the porous base. Honeycomb materials preloaded with thermoplastics or flammable gels. Re-constituted cellulosics: cardboard, partible board, melamine. NASA Re-Entry Tiles

22 Questions Are SRMs for ASTM fire test needed? Can ASTM E05 sub-committees afford SRMs?