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[知识面拓展] 燃油微生物检查的操作手册

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发表于 2014-4-25 14:46:23 | 显示全部楼层 |阅读模式 来自: 中国云南昆明
发一个燃油微生物含量检查的操作标准

Microb Monitor 2
For Detection and Enumeration of Contaminating
Microbes in Fuels, Lubricants and Water.
Instructions  for Use
Please read these instructions  carefully  before testing samples.

Important Notice

The test kit should only be used as part of an investigatory process into contamination in petroleum products and associated water.

The test kit must be used strictly in accordance with these instructions or instructions authorised by ECHA Microbiology Ltd.

The results only relate to the samples taken and not necessarily to other petroleum product in the system. Although  guidance  may  be  sought  by  the  user  on  sampling  and  the  interpretation  of  results,  the responsibility  for carrying  out the sampling and test procedures correctly is that of the end-user and not ECHA Microbiology Ltd.

The test kit is designed to detect a recognised group of micro-organisms of industrial significance, but it is in the nature of microbiology that there may be micro-organisms present which are not detected by the test procedure.

ECHA Microbiology  Ltd does not accept any liability  for any decision or assessment taken or made as a consequence of the results obtained.
Awards and Endorsements:
Aviation Week & Space technology Innovation Award, USA, 1999.
Millennium Product status, UK, 2000
Institute of Petroleum’s Innovation Award 2002.
Recommended test in IATA’s Guidance Material on Microbiological Contamination in Aircraft Fuel Tanks.
Listed in Aircraft Maintenance manuals of Airbus, Boeing, BAE Systems and others.
NATO Codified 6640-99-834-3573
MicrobMonitor2  has been developed and patented by ECHA Microbiology Ltd. and is marketed worldwide by ECHA and their distributors
ECHA Microbiology  Ltd, Units 22 & 23 Willowbrook  Technology  Park, Llandogo Road, St Mellons, Cardiff, UK, CF3 0EF. Tel: + 44 (0) 2920 496321                                                                                                                                                           Fax: +44 (0) 2920 493671 www.microbmonitor.com                                                                                                                                           e.mail: sales@microbmonitor.com
EP066.200111                                                                                 1



1.        PRINCIPLE OF THE MicrobMonitor2   TEST

The test consists of a screw-capped bottle containing a thixotropic nutrient gel that promotes the growth of Bacteria, Yeasts and Moulds. It detects all important petroleum spoilage microbes including Hormoconis (Cladosporium) resinae, Aspergillus, Candida and Pseudomonas. Sterile plastic loops and syringes are supplied for measuring samples into the gel. A sample is added and dispersed in the gel  by  shaking;  the gel then re-sets and during incubation, microbes in the sample reproduce to form visible purple ‘colonies’. The number of colonies formed is a direct estimate of the number of viable microbial particles (colony forming units, cfu) present in the sample. The actual number of colonies is counted or is estimated by reference to the calibration chart supplied. The volume tested can be 0.01 ml (using a sterile measuring loop) or between 0.1 ml and 0.5 ml (using a sterile syringe). The calibrations and estimations of microbial numbers on the chart supplied are adjusted if necessary to fit the volume actually tested.

2.        METHOD OF USE FOR AVIATION FUEL2.1      Examine sample visually.
•        If the sample does NOT contain free water, shake it.
•        If the sample contains any free water agitate it, but avoid mixing the water and fuel phases together.
NB.  If there is sufficient free water present (at least 1 ml) it is recommended that two tests are used to test fuel and water phases separately. This is an IATA recommendation.
IATA also recommend that 1 litre of fuel sample is taken from aircraft tank drains. The MicrobMonitor2 Sample
Bottle can be ordered; it holds 1 litre and is designed to separate water and fuel phases to facilitate testing.

2.2      Break and discard the plastic seal then remove the cap of the MicrobMonitor2 bottle. Place it on a clean surface.

2.3      Add a measured amount of sample to MicrobMonitor2 as described below.

2.3.1   To Test Fuel Phase;
The recommended volume of aviation fuel to test is 0.5 ml; this will detect from 2000 cfu per litre to above
2 x 107 cfu per litre. NB. Testing larger volumes may cause the gel to become progressively cloudy.
•        Open the syringe pack at the handle end and remove the syringe taking care not to touch the lower
barrel and nozzle.
•        Use the syringe to remove fuel from about halfway down the sample until the syringe is more than half full.
•        Expel air and surplus fuel until the collar of the syringe plunger is at the 0.5 ml mark.
•        Transfer the 0.5 ml of fuel to the MicrobMonitor2 and discard the syringe.

2.3.2   To Test Water Phase in an Aircraft or Airfield Fuel Tank Sample;
The recommended volume of water to test is 0.1 ml; this will detect from 10 cfu per ml to above 105 cfu per ml.
•        Open a new syringe pack and remove the syringe as described above.
•        Slightly withdraw the piston of the syringe and insert it through the fuel sample into the middle of the
free water phase underneath.  Press syringe plunger down to expel air and any fuel.
•        Withdraw water from the sample and remove syringe.
•        Expel surplus water until the collar of the syringe plunger is at the 0.1 ml mark.
•        Transfer the 0.1 ml of water to the MicrobMonitor2 and discard the syringe.

2.3.3   To Test Water Phase in a Refinery or Tank Farm Storage Tank or Fuel Cargo Sample;
The recommended volume of water to test is 0.01 ml; (measured with the loops supplied); this will detect from
100 cfu per ml to above 106 cfu per ml.
•        Use a new syringe to remove water from beneath the fuel in the sample and transfer it to a separate sterile
sample container. Do not transfer fuel; traces of fuel on the water will prevent the loop from filling.
•        Open a loop pack at the handle end and remove the loop taking care not to touch the lower part.
•        Immerse the loop in the water and then withdraw it ensuring that the circle of the loop is full.
Alternatively, the syringe can be used to transfer water directly from the sample to the loop.
•        Stab the loop into the MicrobMonitor2  gel, rotating it to transfer the sample to the gel; withdraw the
loop and discard it.

2.4      Re-cap the MicrobMonitor2   bottle and label it along the edge of the bottle with the label provided.

2.5      Tap the bottle firmly to break up the gel.

2.6      Shake the MicrobMonitor2   bottle vigorously for about 30 seconds so that the gel liquefies.

2.7      Immediately flick the gel into the bottom of the bottle to avoid gel adhering to the cap and the neck of the bottle.

2.8        Immediately tap the bottle to make a flat layer of gel on one of the large flat sides.  Ensure that a uniform layer reaching all corners is obtained.

2.9        Keeping the gel on the lower surface of the bottle, incubate the test at approximately 25°C. Observe DAILY for up to 4 days.  If an incubator is not available, use a dark, warm, draught free location at approximately 25 °C. Temperatures lower than 25°C, even if only overnight, will result in slower growth of any microbes present; allow for this delay when interpreting results by ob-serving gels and counting colonies for up to 6 or 7 days.
2



NB.  DO NOT leave a MicrobMonitor2 test in direct light.  DO NOT agitate the gel after the sample has been dispersed in it. Leave the bottle in the same horizontal position during transport, incubation and examination.

2.10     Examine the MicrobMonitor2 after incubation and count (see 2.10.1) or estimate (see 2.10.2) the number of purple colonies, holding the bottle in front of a white background. It is usually not necessary to distinguish between bacteria, yeasts and moulds and a single colony count to include all microbes can be conducted.  Bacterial and yeast colonies will usually appear after 1-2 days and mould colonies (fuzzy appearance) after 2 - 4 days.

NB. A few fuels may cause a slight uniform pale pink or orange coloration in the gel; this should be ignored when counting or estimating colonies. If very large numbers of microbes were present in the sample, individual colonies may not be distinguishable and the whole of the gel becomes purple.
2.10.1  Counting Colonies

If colonies can be counted, determine the exact number present in the test gel.  All colonies in all parts of the bottle should be counted.  A hand lens may be useful.  Marking the position of the colonies with a felt tip pen will assist this procedure.  It is the NUMBER of colonies which is important, not their size.  Rapidly growing, motile bacteria may occasionally produce streaks in the gel; count each streak as one colony. Ignore any air bubbles present in the gel.  Reincubate if necessary, counting additional colonies if they appear.  Use the total colony count to calculate the numbers of microbes in the sample, as described in section 2.11.
2.10.2  Using the Calibration  Chart to Estimate Numbers of Colonies

If colonies are too numerous to count, refer to the interpretation chart on page 6 to estimate the approximate number of colonies in the test gel.  If a sample volume of 0.5 ml or 0.25 ml of fuel or 0.1 ml or 0.01 ml of water was tested, the chart can then  be used to determine the number of microbes in the sample. If a different sample volume was tested, use the estimated colony count to calculate the number of microbes per litre of sample (Equation 1) or ml of sample (Equation 2) as appropriate (see section 2.11).
2.11     Estimating  Numbers of Microbes in Sample

For Tests  of Fuel;If 0.5ml of fuel has been tested, multiply the number of colonies counted or estimated by 2000 to give the
number of microbial cfu per litre of fuel.  If there are no colonies after the specified incubation time (see2.9) there are less than 2000 microbial cfu per litre of fuel. If a different volume of fuel is tested, then a
calculation is made as follows:
Equation 1:                   colonies counted       x 1000  = microbial cfu per litre
Volume tested (ml)

For Tests  of Water Associated  with Fuel:If 0.1 ml of water has been tested, the number of colonies counted or estimated is multiplied by 10 to give
the number of microbial cfu per ml of water.  If there are no colonies after the specified incubation time(see 2.9) there are less than 10 cfu per ml of water.

If 0.01 ml (loopful) of water has been tested, multiply the number of colonies counted or estimated by 100. If there are no colonies after the specified incubation time (see 2.9) there are less than 100 cfu per ml of water.

A calculation must be made as follows if other volumes of water are tested:
Equation 2:                   colonies counted       = microbial cfu per ml
Volume tested (ml)
3.          METHOD OF USE; OTHER FUELS AND OILS AND SURFACE TESTING
3.1        To Test Gas Oil, Diesel Bio-diesel, Gasoline and other Distillate  Fuels;

The test procedure is as for aviation fuel (section 2.) but the recommended volume to test is 0.25 ml; this will detect from 4000 cfu per litre to above 4 x 107 cfu per litre. Larger volumes of the fuel should not be tested as they may not disperse evenly and may also cause the gel to become progressively cloudy. If 0.25 ml of fuel has been tested, multiply the number of colonies counted or estimated by 4000 to determine the number of cfu per litre of fuel.

3.2      To Test Water Associated with Gas Oil, Diesel, Bio-diesel, Gasoline and other Distillate  Fuels (eg Storage Tanks or Equipment Drains);The test procedure is as described in section 2. Add a loopful (0.01 ml) of water sample as described in 2.3.3.
3.3        To Test Lubricating  and Hydraulic  Oils;

Follow the test procedure for aviation fuel (section 2.) but instead of the procedures described in 2.3, add0.01 ml of oil as follows;
•        Open a loop pack at the handle end and remove the loop taking care not to touch the lower part.•        Immerse the loop in the sample and then withdraw it; allow excess oil to drain off but ensure that the
circle of the loop is full.
3

•        Stab the loop into the gel and rotate it to transfer the sample; withdraw the loop and discard it.

This procedure will detect from 100 cfu per ml to above 106 cfu per ml.  Volumes in excess of 0.01 ml of oil
will not disperse adequately in the test gel.  If  0.01 ml has been tested, multiply the number of colonies
counted or estimated by 100 to give the number of microbial cfu per ml of oil. If there are no colonies after
the specified incubation time there are less than 100 cfu per ml of oil.
3.4      To Test Surfaces
Use a sterile swab (available from ECHA) to rub the surface to be tested, rotating the handle between the fingers so that all of the swab contacts the surface.  If possible swab a known area. Avoid touching the cotton end of the   swab  and  the  shaft  within  80  mm  of  the  cotton  end.  Thrust  the  swab  into  a MicrobMonitor2  gel, agitate it briskly for about 15 seconds and then withdraw it and discard it to waste. Shake the test bottle and proceed as in 2.4—2.10. The number of colonies counted or estimated is the number of cfu recovered from the area swabbed.

4.        DISPOSAL
Tests showing any positive results contain microbial cultures and should be handled carefully. Avoid touching the inside of the bottle or cap. Dispose of used tests showing microbial growth by incineration, or by disinfection followed by disposal. Wash your hands and the work surface after disposal with antibacterial soap.
Disinfection can be accomplished by careful addition to each used test bottle of two of the “Aquatabs” (chlorine release pills) provided in the MicrobMonitor2 kits. Recap the bottle and shake vigorously for 30 seconds then leave for 24 hours. After sterilization, bottles should be disposed of in accordance with local waste disposal regulations. Unused or negative tests can be disposed of as normal waste In accordance with local waste disposal regulations.

5.        STORAGE AND SHELF LIFE
The shelf life of MicrobMonitor2  is 1 year from the date of production, the expiry date is printed on the batch label of each MicrobMonitor2 box.  Store MicrobMonitor2 tests between 2 to 22°C, in the dark.  The expiry date applies only to product stored as stipulated.  If refrigerated (2 – 8°C) the test will usually still be useable for up to a year beyond the designated expiry date.  Do not store MicrobMonitor2  frozen.  Exposure to freezing temperatures during transport is acceptable. Avoid exposure of MicrobMonitor2 tests to light during storage and use. A slightly pink discolouration in the MicrobMonitor2 gel may develop over time during storage but this will not affect the performance of the test.

6.        ADVICE AND TECHNICAL SERVICE
More  information  on  sampling  and  testing  fuel  and  oil  systems  is  accessible  on  www.microbmonitor.com
or www.echamicrobiology.co.uk

ECHA Microbiology Ltd. manufactures the MicrobMonitor2  test and provides a full technical service to support this product. ECHA also have a comprehensive laboratory testing facility and offer consultancy and on site attendance. Courses on microbial problems are available.  Ancillary items (sample bottles, swabs, incubators etc) are available from ECHA as well as other test kits for detecting Sulphate Reducing Bacteria (the Sig Sulphide test) and for assaying biocide (the Biocide Rapide test).
The following comments may be of assistance when conducting routine testing or an investigation. IATA and other organizations recommend routine testing and early remedial action if limit values are exceeded.

Fuel:
There is no consensus of opinion or standard for the permissible limits of microbial contamination of fuel.  It is usual
to apply more stringent standards to aviation fuel than to diesel or heating fuel.  More stringent standards are also
applied to fuel that is intended for long-term storage. Tank drain and tank bottom samples are useful.  They will
usually be more contaminated than the bulk of the fuel in a tank.  If a high count is obtained from such a sample
it would then be prudent to test more samples from the system. We recommend testing layer samples in a storage
tank and/or take-off and final delivery samples.  Samples upstream and downstream of filters (particularly on an
airfield) are useful.  For aircraft test fuel tank drain samples as specified in the Aircraft Maintenance Manual.  IATA
publication Guidance Material 2005, proposes sampling procedures and frequencies for aircraft and warning and
action limit values; below 4000 cfu per litre is considered negligible. IATA recommend that significant positive results
are confirmed by a retest. IATA also recommend that the efficacy of any biocide treatment be validated by further
tests. Any trend of an increase in numbers in successive tests of similar samples should be considered significant.
Water  Associated  with Fuel or Oil:
Because microbes proliferate in the water phase, they will generally be far more numerous in water than in the fuel
or oil above it. Consequently different standards must be applied to fuel/oil and water phases. If water associated with storage tank fuel/oil contains 105 cfu per ml or more it is possible that microbial proliferation has started, particularly if the colony appearance and their growth rate indicates the presence of moulds and yeasts. More
water and fuel samples should be tested to determine the extent of contamination in the system.  It is prudent to test storage tank water for corrosive Sulphate Reducing Bacteria (SRB) if it is found to be highly contaminated by a MicrobMonitor2  test. SRB may be detected using a different test kit called a Sig Sulphide test. Water in aircraft fuel tanks should be cleaner than fuel storage tank water.  IATA proposes limit values in aircraft fuel tank drain samples of up to 1000 cfu per ml as an indication of negligible contamination, 1000-10000 as moderate contamination and above 10000 cfu per ml as heavy contamination.  Results should be confirmed by a retest.

Oils:
If oil contains 104 cfu per ml or more it is probable that microbial proliferation has started.  Take and test samples
throughout the system (sump bottom, header tank, before and after a purifier or filter etc.).

EP066.210111 Microbmonitor2 Instruction for Use_Web Use.pdf

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燃油微生物检查

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发表于 2014-4-26 10:48:26 | 显示全部楼层 来自: 中国湖南长沙
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发表于 2014-4-26 12:34:30 | 显示全部楼层 来自: 中国湖北武汉
这是大修厂做的工作额
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