PowerPoint Presentation - · PDF file04.04.2017 · 4/6/2017 2 THE QUEEN [S AWARDS FOR ENTERPRISE: FOR INNOVATION 2014 FOR INTERNATIONAL TRADE 2012 The size and

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THE QUEEN’S AWARDS FOR ENTERPRISE:FOR INNOVATION 2014FOR INTERNATIONAL TRADE 2012

www.seta-analytics.com

Automatic Particle Counting (IP 565) – In Context

Ian Mylrea

R&D Manager

Stanhope Seta



• Laboratory and field apparatus

• Very simple to operate – single button press

• Test takes 3 minutes

• Typically determines level of dirt particles and water droplets from 4 µm to 30 µm

• Test methods

– IP 565

– ASTM D7619

• Similar, small procedural differences

– ASTM D7619 scope includes diesel

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Particle Counting Refresher



What is measured?

• All particles >= 4 micron

– Entrained water droplets

– Dirt

• Metal fragments

• Oxides

• Microbes

• Yeasts

• Dust

• …

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• IP 565 contains a water removal Annex

• Use a chemical to dissolve the water

• Effective to eliminate free water from being counted

– proven during Energy Institute trial

• Based on the US Army presentation –most samples do not require this

• More work going on at the EI



Specifications

• Report only

– Def Stan 91-91

– MIL-DTL-83133 (US)

– MIL-DTL-5624 (US)

– AFQRJOS Issue 28

• At point of manufacture

• MIL-STD-3004 (proposal) NEWIASH 2015 Particle Count Limits Recommendation for Aviation (J.Schmitigal)

4THE QUEEN’S AWARDS FOR ENTERPRISE:FOR INNOVATION 2014FOR INTERNATIONAL TRADE 2012


Collimating Lens

Laser

Focusing Lens

Measurement Cell

Detector

Principle of operation



• Cell shape causes long particles to align

• This ensures that the longest axis contributes to the shadow cast on the sensor.


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The size and shape of the cell accelerates the sample, increasing separation between particles

This reduces the risk of overlapping particles being measured as a single particle.




mV

t

t

• Reference voltage

• Particle casts a shadow on the sensor

• Voltage drop on sensor

• Proportional to size of particle mV




Sizing

• The voltage drop and duration is converted into an equivalent particle size based on a sphere

• Particles are put into ‘bin’ sizes 4, 6, 14 micron…

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4 micron 6 micron 14 micron

3000 counts 1000 counts 100 counts

Converted to ISO code 19/17/14 for example



ISO codes

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• To reduce the amount of information, whilst maintaining usefulness

• 19/17/14 means

– 2500 to 5000 particles of 4 micron or more



• US MIL-STD-3004 Proposal 19/17/14/13

– As above




Calibration/ performance

• Calibration & equations according to ISO 11171

• ISO11171 defines the particle counter and accuracy requirements

• Tight performance…..based on specific calibration dust traceable via NIST

• Update to the calibration specification required due to change to NIST reference standard

– Likely to increase counts slightly

– Precision unlikely to be affected

– Calibration type to be reported – note going into test methods



How big is a micron?

• Particle counters report per mL (millilitre)

• 1 mL is 1000000000000 cubic microns

• Code 19 = approx. 3000 particles for example

• 4 micron sphere has a volume of 32 cubic microns

• Total volume taken up by 3000 particles at 4 micron is 32 x 3000 = 96000 cubic microns

• 0.00000096% of the available space in 1 mL taken up by particles

• Particle counts are presenting the volume of particles in the fuel

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Human hair 60 microns diameter

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Gravimetric particulate methods

• Max is 1.0 mg/L (1 part per million)

• Measure of weight

– Metal fragments weigh more (iron oxide 3 g/cm3)

– Sand weighs more (Silica 1.5 g/cm3)

– Microbes are water based density = 1 g/cm3

– Gravimetric test (IP 423/ ASTM D5452) requires a drying step

• dry microbes weigh less (water removed)

• 90% water

• Mass when dry will be 10 x LESS g

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• Drying process• Water is removed• Large reduction in

weight



Interim Summary

• Particle counting is a volumetric measure of dirt and water, or dirt only (using water chemical removal)

• Contamination test method (ASTM D 5452/IP 423) measures dry weight

• Question: What blocks filters…..weight or volume?



Quality of Aviation Fuel Available in the UK Annual Survey 2009 to 2013 NEW

• Prepared by Intertek

• Funded by UK Energy Institute

• Comparison from 1986 to 2013

• 35 other such reports going back to 1974

• Main batches released during 2009 to 2013

• Large proportion of imports – partly representative of jet fuel world wide

• Data from over 4000 batches

• Publication imminent

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US Army Survey NEW

• 2015 IASH Particle Count Limits Recommendation for Aviation Fuel - Joel Schmitigal

• Gravimetric

• Sept 2012 to July 2015

• 1614 samples analysed (96% by IP 565)

– 85% passed both gravimetric (1.0 mg/L) and particle counting (19/17/14/13) limits

– 15% failed either GM, APC or both

– Gravimetric has quite wide precision

– Particle counters detect water as well

– Particle counters limited to >4 micron



US Army Summary



Apply this to the UK Survey Data – 19/17/14/13

• Caveat – estimate only – no link in the survey between levels in one size band and another –this would require a separate detailed study

• Analyse the EI Quality of AVTUR Survey data as if 19/17/14/13

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19/17/14/13 hypothetical failure rate 5%

% hypothetically failed by IP 565 if using 19/17/14/13

Size (micron) 2009 2010 2011 2012 2013Avera

ge>19 4 5.7 5.2 3.1 3.7 5.7 4.7

>17 6 5.2 6.2 4.4 3.9 7 5.3>14 14 1.2 2.9 1.5 1.9 2.8 2.1

>13 30 0 0 0 0.1 0.2 0.1

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• Using the water removal approach would reduce this figure significantly



Thought provoking procedure – 19/17/14/13could IP 565 be used to screen fuels?

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Test by IP 565

Fuel PASSES19/17/14/13

Fuel suitable

Fuel FAILS19/17/14/13

IP 423/ ASTM 5452 Contamination Test, with repeat tests and visual inspection

ASTM D3240 free water test

IP 565 with water removal

Fuel suitable

Fuel PASSES19/17/14/13

Fuel FAILS19/17/14/13

95% approx.



Future thoughts

• EI capturing data to set levels

• C versus B calibration

• Smaller particles than 4 micorn

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PowerPoint Presentation - · PDF file04.04.2017 · 4/6/2017 2 THE QUEEN [S AWARDS FOR ENTERPRISE: FOR INNOVATION 2014 FOR INTERNATIONAL TRADE 2012 The size and