Overview about the PTB Ex Proficiency Testing Scheme - Status Report -

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

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

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

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

Proficiency Testing Scheme

Proficiency Testing Scheme Program 1 “Explosion Pressure” Program 2 “Intrinsic Safety” Current Programs 2014 Program 3 “Flame Transmission” Program 4 “Temperature Classification”

Program “Flame Transmission - FT” 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” • Normative background: IEC 60079-1 • 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

Productionqualityandtoleranceof a nozzle Homogeneity • 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)

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

Test resultsandevaluationoftheresults 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 7.1.2 ) • ... 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.

Test resultsandevaluationoftheresults Proficiency assessment (without statistical basis!)

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

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

Program “TemperatureClassification” • Normative background: IEC 60079-0 • 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

Program “TemperatureClassification - 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

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

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

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

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

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

Test resultsandevaluationoftheresults Temperature classification

Further activitiesconcerning „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:

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

Feedback ofparticipants +Programs are well managed, well supported + Participation quite beneficial +We are particularly grateful for the level of support that ourexplosiontest 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. -)

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

Feedback ofparticipants Future program ideas -testing for purged/pressurized enclosures, such as purge effectiveness - Flameproof motor test - [ 10 ] Overpressure test (IEC 60079-1, cl. 15.1.3). - [ 09 ] Measurement of capacitance (IEC 60079-0, cl. 26.15). - [ 08 ] Clearances, creepage distances and separations (IEC 60079-7, cls. 43 and 4.4; IEC 60079-11, cl. 6.3; IEC 60079-15, cl. 6.4). - [ 07 ] Spark ignition and surface temperature of cells and batteries (IEC 60079-11, cl. 10.5.3). - [ 06 ] Surface resistance test (IEC 60079-0, cl. 26.13). - [ 05 ] Tests for apparatus containing piezoelectric devices (IEC 60079-11, 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 60079-7 Annex E (Power dissipation and temperature calculations) Test according to 6.7 - Comformityassessment of Ex-d equipment special cases (Breathing devices, Very small enclosures, Conduits, Gas analysers - Performance test of gas detectors and sinters according to 60079-1, especially test of surface temperatureof 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

PTB Ex PTS – Cost evaluation Estimated costs of the programs: • Cost of test samples • Test Sample “EP” & “FT” ≈ 3,000.00 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 yearand 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

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 60079-1”) • 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

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

Thank you for your attention… Lisa Zater, B.Eng. Working Group 3.54 "International Harmonization in Explosion Protection"Physikalisch-Technische Bundesanstalt (PTB)Bundesallee 100, 38116 Braunschweig, GermanyDirect Phone: +49 (0)531 592-3547 Fax: +49 (0)531 592-693582 Email: lisa.zater@ptb.de Dipl.-Ing. (FH) Tim Krause, M.Eng.Working Group 3.54 "International Harmonization in Explosion Protection"Physikalisch-Technische Bundesanstalt (PTB)Bundesallee 100, 38116 Braunschweig, GermanyDirect Phone: +49 (0)531 592-3582 Fax: +49 (0)531 592-693582 Email: tim.krause@ptb.de

Overview about the PTB Ex Proficiency Testing Scheme - Status Report -