the brightness of the fluorescence of the test
level of your fuel, you can proceed with the free water
pad with that of the standards. The numbers
test. For this test, you will use the AEL Mk II free water
located directly above the standards will
detector as well as some parts of the AEL Mk III.
indicate the free water content in ppm. If the
chart reading is 5 ppm or less, then the level of
AEL Mk II. The AEL Mk II free water detector
free water is acceptable. A chart reading of 5
consists of three main parts: (1) a view box containing
ppm or less equates to an actual limit of about
an ultraviolet light source; (2) a set of printed standards,
40 ppm or less. You will not need to make
indicating 0, 5, 10, and 20 ppm; and (3) some water
corrections for sample size.
detector test pads. To maintain detector accuracy, you
must replace the printed standards every 6 months. The
10. Your last step is to drain the fuel from the flask
water detection pads are extremely sensitive to moisture
of the AEL Mk II through the tygon tubing.
in the air. To avoid false readings, avoid drawing air
Up to now, we have discussed sampling and testing
through these pads at times other than when your fuel
requirements and procedures for F-76. In the following
sample has passed completely through the pad. Keep
sections, we will discuss the procedures you will need
these precautions in mind as you take the following
to use for F-44, commonly called JP-5.
1. Using the same fuel sample bottle you used
with the AEL Mk III, fill the bottle to the 200
Although most of your fuel sampling
mL mark with F-76.
responsibilities will involve F-76, you also will be
involved with maintaining the quality of F-44. F-44 has
2. Open a free water detector envelope. Using the
two principal uses on board gas turbine-powered ships.
forceps, pick up the detector pad and place it,
Its primary use is for the service of aircraft. Its secondary
orange side up, on the contaminated fuel
use is for the ship's boats. Maintaining a high quality of
detector filter base. Attach the bottle receiver to
this product is very important. As you read about the
the filter base and plug in the ground wire jack.
sampling and testing procedures for F-44, notice how
3. Check to make certain the fuel flask is empty
the quality requirements for F-44 are much more
and the drain valve is closed.
stringent than those for F-76.
4. Shake the sample bottle vigorously for at least
30 seconds. Immediately turn on the vacuum
In sampling F-44, you will use the same visual
pump. Unscrew the bottle cap and place the
sampling criteria (clear and bright) as you would for
bottle receiver and pad holder assembly firmly
F-76. The main difference in the sampling requirements
over the end of the sample bottle, making sure
is that you must sample F-44 fuels more frequently, The
the entire threaded portion of the bottle top is
inserted into the bottle receiver.
conditions under which you must sample F44 and the
frequency with which you must take these samples are
5. Pick up the entire assembly, invert it, and insert
listed in NSTM, chapter 542, "Gasoline and JP-5 Fuel
the pad holder end into the fuel flask of the AEL
Systems." As we are unable to cover the multitude of
Mk III. Do steps 4 and 5 quickly to keep the
conditions and circumstances within the scope of this
free water in suspension.
TRAMAN, we recommend you consult NSTM, chapter
6. Observe the filtration process. Once the entire
542, for detailed instructions.
sample has passed through the detector pad,
turn off the vacuum pump. Remove the bottle
and the bottle receiver.
You will basically use the same tests and testing
procedures for F-44 as you would for F-76. The main
7. Using your forceps, remove the detector pad
difference is that the testing requirements for F-44 are
from the filter base and place it, orange side up,
stricter than those for F-76. The stricter requirements for
in the free water detector slide depression.
F-44 apply mainly to the following maximum allowable
8. Hold the light switch in the ON position and
insert the slide containing the test pad.
9. Look through the view port of the box. To
determine the amount of free water, compare
Free water content must not exceed 5 ppm.