overview about the ptb ex proficiency testing scheme - status report -

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

Lisa Zater, Tim Krause , Uwe Klausmeyer26th of August 2014

ExTAG WG 10

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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

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Progress report

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

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Progress report

Status of current programs “FT” & “TC”

• Coverage: 82 %

• Coverage: 40 %

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Proficiency Testing Scheme

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Proficiency Testing Scheme

Program 1 “Explosion Pressure” Program 2 “Intrinsic Safety”

Program 3 “Flame Transmission” Program 4 “Temperature Classification”

CURRENT PROGRAMS 2014

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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”

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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

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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

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Test results and evaluation of the results

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

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Test results and evaluation of the results

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

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Test results and evaluation of the results

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

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Test results and evaluation of the results

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

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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 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.

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Test results and evaluation of the results

Proficiency assessment (without statistical basis!)

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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

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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”

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Program “Temperature Classification”

• 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

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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

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Test results and evaluation of the results

Determination of hotspots – assigned value and participants’ results

Copper: homogeneous temperature distribution

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Test results and evaluation of the results

• Glass surface at level 3

Determination of temperature – participants’ results

9 test results are under the range!!!

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Test results and evaluation of the results

• Plastic surface at level 3

Determination of temperature – participants’ results

10 test results are under the range!!!

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Test results and evaluation of the results

• Copper surface at level 3

Determination of temperature – participants’ results

10 test results are under the range!!!

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Test results and evaluation of the results

• Steel surface at level 3

Determination of temperature – participants’ results

7 test results are under the range!!!

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Test results and evaluation of the results

Temperature classification

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Test results and evaluation of the results

Temperature classification

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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:

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Feedback of participants of PT programs FT/TC

Results of the survey

Category

Topic/Question

Category concept processing support reporting program “FT” program “TC” too long? appropriate?

Average evaluation 9,6 9,6 9,3 8,8 28,6 33,6 1 X 8 X

Performance of PROGRAMS

Overall performance of the programs “FT” and “TC” in relation to:

Estimated in house operation and processing

time (in hours)

Was this time in your opinion:

* out of 10 possible points

The evaluation consists of 9 results, that have been received by August 21st 2014.

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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. -)

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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 21st 2014.

Category

Topic/Question

Categoryselection of

topics for presentations

quality of presentations

time schedule during the workshops

more less the same amount

“FT” “TC”

Average evaluation 8,5 8,7 9,3 1X 0 5X 9,2 9,2

Overall performance of the workshops:

Performance of WORKSHOPS

Please evaluate the following aspects concerning the workshops:

How would you appreciate the number of guest presentations

during the workshop? Would you like to hear:

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Feedback of participants

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- 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 60079-1, 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

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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 138,000Costs of HR since 2009 for development and operation of the PT programs• “EP” & “FT” ≈ EUR 300,000• “SI” ≈ EUR 150,000• “TC” ≈ EUR 100,000Overall costs 2009 until 2014: EUR 1,048,000Estimated 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

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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

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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

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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, 38116 Braunschweig, GermanyDirect Phone: +49 (0)531 592-3582

Fax: +49 (0)531 592-693582Email: tim.krause@ptb.de

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)531 592-693582Email: lisa.zater@ptb.de