- Repeat step 4 for the test membrane filter. Record the membrane filter masses.
- Take a clean field monitor, mark for identification, rinse with filtered flushing fluid, and insert a
clean support pad.
- Using clean forceps, place the weighed control membrane filter centrally on the support pad in the
field monitor and place the weighed test membrane filter on top of the control membrane filter.
Assemble the two parts of the field monitor, ensuring that the membrane filters are firmly clamped
inside and the protective plugs are in position.
- Record the monitor identification.
Collecting an Aviation Turbine Fuel Sample.
Fix the self-sealing connection to the sampling point ensuring that the dust cap at the exposed ends is in
place. The sampling connection is normally left in place at all times.
Unscrew the field monitoring casing.
Remove the bottom protective plug from the monitor and place it in a clean safe place.
Place the monitor in its casing.
Remove the other protective plug from the monitor and place it in a clean safe place.
Reassemble the monitor casing by hand-tightening only.
Ensure that the flushing line is connected to the selector valve. Return the free end of the flushing line to
the sampling assembly downstream of the field monitor or lead it directly into a receiver.
Ensure that the flexible sampling line is connected to the bottom of the monitor casing and lead the free
end to the graduated sample receiver.
Remove the dust caps from the sampling connection and the flexible pressure hose connector, and
connect the sampling apparatus to the sampling connection with the selector valve in the "off" position.
When the desired fuel flow and pressure conditions are established in the line or hose, operate the
selector valve to the "flush" position.
When at least 2 L of fuel are collected, operate the selector valve to the "sample" position. During
normal operations a line pressure of 35 psi (0.24 MPa) minimum is suitable to obtain a reasonable
sampling rate. Constant line pressure should be maintained during sampling.
Take a 3.785-L (1-gallon) to 5-L fuel sample if conditions permit. When the required amount of fuel is
collected, operate the selector valve to the "off" position.
After sampling is completed, allow 1 minute to pass; then disconnect the sampling unit from the sampling
connection and replace the dust caps.
Remove the field monitor from its casing and replace the protective plugs. Do not open the field monitors
under any circumstances before returning them to the laboratory. If they are opened, the membrane
filters and the field monitor must be discarded.
Preparing the Test Apparatus.
Wash the petri dishes and supports with warm water containing detergent. Rinse with warm water and
then with distilled water.
Rinse thoroughly with filtered isopropyl alcohol and then with filtered petroleum ether or 1,1,2-trichloro-
1,2,2-trifluoroethane.
Drain for a few seconds and then air or oven dry.
Ensure that all glass and plastic tubing attached to the solvent filtering dispenser is clean by flushing
thoroughly with filtered petroleum ether or 1,1,2-trichloro-1,2,2-trifluoroethane.
Perform the Test Procedure.
Assemble the apparatus with the sample monitor in place on the stopper of the vacuum flask.
Place the tip of the delivery spout of the solvent filtering dispenser in direct contact with the monitor inlet
hole. Introduce petroleum ether of 1,1,2-trichloro-1,2,2-trifluoroethane until the monitor is full.
Apply a vacuum to the flask and allow approximately 250 ml of petroleum ether or 1,1,2-trichloro-1,2,2-
trifluoroethane to pass from the solvent filtering dispenser through the monitor and into the vacuum flask.
Remove the solvent filtering dispenser and slowly release the vacuum.
Remove the monitor from the stopper of the vacuum flask and carefully dismantle it in an upright
position.
Carefully remove the test and control membrane filters and place side by side on clean glass supports in
the clean, covered petri dishes.
3-4
QM 5183
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