PTB Ex Proficiency Testing Scheme

Report
ExTAG WG 10
Overview about the PTB Ex Proficiency Testing Scheme
- Status Report -
Lisa Zater, Tim Krause , Uwe Klausmeyer
26th of August 2014
1
Progress report
Status of programs “EP”, “SI”, “FT” and “TC”
• Program 1 “Explosion Pressure” • Program 3 “Flame Transmission”
Number of participating
Number of participating
laboratories: 47
laboratories: 49
• Program 2 “Spark Ignition”
Number of participating
laboratories: 45
• Program 4 “Temperature
Classification”
Number of participating
laboratories: 46
A total of 63 participating
laboratories from 30 countries!
2
Progress report
Status of programs “EP”, “SI”, “FT” and “TC”
3
Progress report
Status of current programs “FT” & “TC”
• Coverage: 82 %
• Coverage: 40 %
4
Proficiency Testing Scheme
5
Proficiency Testing Scheme
Program 1 “Explosion Pressure”
Program 3 “Flame Transmission”
Program 2 “Intrinsic Safety”
Program 4 “Temperature Classification”
6
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)
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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
8
Production quality and tolerance of 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)
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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
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
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.
14
Test results and evaluation of the results
Proficiency assessment (without statistical basis!)
15
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
16
Program “Temperature Classification - TC”
Status
• Number of participating laboratories: 46
• Uploaded results of Phase I: 45 (a ExTL will only take
part in Phase II.)
17
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
18
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
20
Test results and evaluation of the results
Determination of temperature – participants’ results
• Glass surface at level 3
9 test results are under the range!!!
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Test results and evaluation of the results
Determination of temperature – participants’ results
• Plastic surface at level 3
10 test results are under the range!!!
22
Test results and evaluation of the results
Determination of temperature – participants’ results
• Copper surface at level 3
10 test results are under the range!!!
23
Test results and evaluation of the results
Determination of temperature – participants’ results
• Steel surface at level 3
7 test results are under the range!!!
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Test results and evaluation of the results
Temperature classification
25
Test results and evaluation of the results
Temperature classification
26
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
Reporting phase:
• Updating of new assigned value with repeated test
results
• Final report
27
Feedback of participants of PT programs FT/TC
Results of the survey
The evaluation consists of 9 results, that have been
received by August 21st 2014.
Performance of PROGRAMS
Category
Topic/Question
Category
Average evaluation
Overall performance of the programs “FT”
and “TC” in relation to:
Estimated in house
operation and processing
time (in hours)
concept processing support reporting program “FT” program “TC”
9,6
9,6
9,3
8,8
28,6
33,6
* out
Was this time in your
opinion:
too long?
appropriate?
1X
8X
of 10 possible points
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Feedback of participants
Comments about the programs (pos. +/neg. -)
+ 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
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Feedback of participants of the Workshops
Results of the survey
The evaluation consists of 9 results, that have been
received by August 21st 2014.
Performance of WORKSHOPS
Category
Topic/Question
Category
Average evaluation
Please evaluate the following aspects
concerning the workshops:
selection of
quality of
topics for
presentations
presentations
8,5
8,7
How would you appreciate the
number of guest presentations
during the workshop? Would you
like to hear:
Overall performance of
the workshops:
time schedule
during the
workshops
more
less
the same
amount
“FT”
“TC”
9,3
1X
0
5X
9,2
9,2
* out of 10 possible points
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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
31
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 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
32
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
33
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…
Lisa Zater, B.Eng.
Working Group 3.54 "International Harmonization in
Explosion Protection"
Physikalisch-Technische Bundesanstalt (PTB)
Bundesallee 100, 38116 Braunschweig, Germany
Direct Phone: +49 (0)531 592-3547
Fax: +49 (0)531 592-693582
Email: [email protected]
Dipl.-Ing. (FH) Tim Krause, M.Eng.
Working Group 3.54 "International Harmonization in
Explosion Protection"
Physikalisch-Technische Bundesanstalt (PTB)
Bundesallee 100, 38116 Braunschweig, Germany
Direct Phone: +49 (0)531 592-3582
Fax: +49 (0)531 592-693582
Email: [email protected]
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