1 Overview about the PTB Ex Proficiency Testing Scheme - Status Report - Lisa Zater, Tim Krause, Uwe Klausmeyer 26 th of August 2014 ExTAG WG 10

2 Progress report Status of programs “EP”, “SI”, “FT” and “TC” A total of 63 participating laboratories from 30 countries! Program 3 “Flame Transmission” Number of participating laboratories: 49 Program 4 “Temperature Classification” Number of participating laboratories: 46 Program 1 “Explosion Pressure” Number of participating laboratories: 47 Program 2 “Spark Ignition” Number of participating laboratories: 45

3 Progress report Status of programs “EP”, “SI”, “FT” and “TC”

4 Progress report Status of current programs “FT” & “TC” Coverage: 82 % Coverage: 40 %

5 Proficiency Testing Scheme

6 Program 1 “Explosion Pressure”Program 2 “Intrinsic Safety” Program 3 “Flame Transmission”Program 4 “Temperature Classification”

7 Status Number of participating laboratories: 48 (1 straggler) Uploaded results in Phase I: 45 Uploaded results in Phase II: 14 (two laboratories provide their results only in Phase II) Program “Flame Transmission - FT”

8 Normative background: IEC Characteristic of interest: Property of flame transmission for three different nozzles (ø 0.7 mm, ø 0.8 mm, ø 0.9 mm) Principle: The gas-air mixture filled chambers are connected via flange with three exchangeable nozzles. After ignition in Pipe A the participant observes if there is a flame transmission into Pipe B or not. Gas-air mixture: (27.5 ± 1.5) % Hydrogen (IIC) Tests: 10 ignitions per nozzle

9 Production quality and tolerance of a nozzle Drill hole diameters of the nozzles: [(0.7 / 0.8 / 0.9) ± 0.01] mm Visual check of the quality/condition of the nozzle countersink at the inlet and outlet (before and after ignitions) Homogeneity

10 Test results and evaluation of the results Bar-charts of the participants’ results of Phase I compared to Phase II with the assigned value

11 Test results and evaluation of the results Bar-charts of the participants’ results of Phase I compared to Phase II with the assigned value

12 Test results and evaluation of the results Bar-charts of the participants’ results of Phase I compared to Phase II with the assigned value

13 Test results and evaluation of the results Bar-charts of the participants’ results of Phase I compared to Phase II with the assigned value

14 Test results and evaluation of the results Proficiency assessment It is not intended to perform the proficiency assessment at this stage of the program. The assessment criteria are to be defined by discussion with the community. A common proposal is to use the standard deviation for the proficiency assessment (according to Standard ISO 13528; clause )... but... The use of spread parameters like variance or standard deviation for describing the results doesn’t make sense in this program due to the small number of ignitions n (small number of independent yes/no experiments). Statistically the statement of the spread parameters would not make sense.

15 Test results and evaluation of the results Proficiency assessment (without statistical basis!)

16 Test results and evaluation of the results Bar chart of the comparison of total bias (absolute) for all participants between Phase I and Phase II

17 Status Number of participating laboratories: 46 Uploaded results of Phase I: 45 (a ExTL will only take part in Phase II.) Program “Temperature Classification - TC”

18 Program “Temperature Classification” Normative background: IEC Measurand of interest: maximum surface temperature Principle: Determination of the hotspot and measuring the maximum surface temperatures at different surfaces (glass, plastic, copper and steel) Scope: three power levels for different temperature classes at four surfaces

19 Program “Temperature Classification - TC” Additional hardware – Power supply controller The same effective wattage of each heating cartridge can be ensured. The effective wattage of heating cartridge remains constant by changing of a local power supply.  to ensure homogeneity

20 Test results and evaluation of the results Determination of hotspots – assigned value and participants’ results Copper: homogeneous temperature distribution

21 Test results and evaluation of the results Glass surface at level 3 Determination of temperature – participants’ results 9 test results are under the range!!!

22 Test results and evaluation of the results Plastic surface at level 3 Determination of temperature – participants’ results 10 test results are under the range!!!

23 Test results and evaluation of the results Copper surface at level 3 Determination of temperature – participants’ results 10 test results are under the range!!!

24 Test results and evaluation of the results Steel surface at level 3 Determination of temperature – participants’ results 7 test results are under the range!!!

25 Test results and evaluation of the results Temperature classification

26 Test results and evaluation of the results Temperature classification

27 Further activities concerning „TC“ Phase II: Testlaboratories, whose results were significantly lower than range, have been contacted and offered suggestions to improve performance procedures They now have the chance to repeat tests and upload new results Updating of new assigned value with repeated test results Final report Reporting phase:

28 Feedback of participants of PT programs FT/TC Results of the survey * out of 10 possible points The evaluation consists of 9 results, that have been received by August 21 st 2014.

29 Feedback of participants + Programs are well managed, well supported + Participation quite beneficial + We are particularly grateful for the level of support that our explosiontest lab personnel received in troubleshooting and fixing fundamental issues with our test equipment. This has made a dramatic improvement in the quality and consistency of test results. + Participation has given us greater confidence in the technical work developed in our testing laboratory + Congratulations to all members and supporters of the PTB Ex PT scheme; we reaffirm our desire to encourage and to take part in new proficiency programs conceived with similar format and organization. + Very useful comparison of practice - Reports are using too much of mathematics for the value of information Comments about the programs (pos. +/neg. -)

30 Feedback of participants of the Workshops Results of the survey * out of 10 possible points The evaluation consists of 9 results, that have been received by August 21 st 2014.

31 Feedback of participants Future program ideas - testing for purged/pressurized enclosures, such as purge effectiveness - Flameproof motor test - [ 10 ] Overpressure test (IEC , cl ). - [ 09 ] Measurement of capacitance (IEC , cl ). - [ 08 ] Clearances, creepage distances and separations (IEC , cls. 43 and 4.4; IEC , cl. 6.3; IEC , cl. 6.4). - [ 07 ] Spark ignition and surface temperature of cells and batteries (IEC , cl ). - [ 06 ] Surface resistance test (IEC , cl ). - [ 05 ] Tests for apparatus containing piezoelectric devices (IEC , cl. 10.7). (10 = highest priority – 0 = lowest priority) - Thermal endurance followed by IP test - Segregation measurement of terminals - Temperature class determination of Ex-e terminal boxes according to IEC Annex E (Power dissipation and temperature calculations) Test according to Comformity assessment of Ex-d equipment special cases (Breathing devices, Very small enclosures, Conduits, Gas analysers - Performance test of gas detectors and sinters according to , especially test of surface temperature of sinter during the explosion tests. - Temperature measurement program with complex and different temperature sources in one unit. - Maximum pore size of sinters - Surface Resistivity Tests. IP5/6X Dust tests

32 PTB Ex PTS – Cost evaluation Estimated costs of the programs: Cost of test samples Test Sample “EP” & “FT” ≈ 3, x 60 copies = EUR 180,000 Test Sample “SI” ≈ 4,000 x 45 copies = EUR 180,000 Test Sample “TC” ≈ 3,000 € x 46 copies = EUR 138,000 Costs of HR since 2009 for development and operation of the PT programs “EP” & “FT” ≈ EUR 300,000 “SI” ≈ EUR 150,000 “TC” ≈ EUR 100,000 Overall costs 2009 until 2014: EUR 1,048,000 Estimated overall HR/sample costs per year assuming the development of one new PT program per year and processing one program per year: EUR 300,000. PTB would be happy to receive EUR 3,000 per laboratory and year, the rest is covered by PTB

33 Further activities Drafting a best practice paper for discussion with the community as a result of the program FT ( e.g. “Best practice in tests for non-transmission of an internal ignition in compliance with ISO ”) Continuous improvement process of the Ex Proficiency Testing Scheme (e.g. participant surveys) Development of potential new PT programs Which programs should be started in 2015 ? Discussion about consequences for the scope of an ExTL in case of poor response and measurement quality and consequences for non-performing ExTLs

34 Further activities Discussion about the involvement of ExTL candidates in the Ex PT Scheme respective individual programs ordered by the assessment team for the on site assessment Discussion about overhead costs for providing the PT programs (plan, validation, samples, reports, daily support,...) Discussion about the inhouse work load caused by Ex PT programs, max. number of working hours

35 Thank you for your attention… Dipl.-Ing. (FH) Tim Krause, M.Eng. Working Group 3.54 "International Harmonization in Explosion Protection" Physikalisch-Technische Bundesanstalt (PTB) Bundesallee 100, Braunschweig, Germany Direct Phone: +49 (0) Fax: +49 (0) Lisa Zater, B.Eng. Working Group 3.54 "International Harmonization in Explosion Protection" Physikalisch-Technische Bundesanstalt (PTB) Bundesallee 100, Braunschweig, Germany Direct Phone: +49 (0) Fax: +49 (0)