Figure 2-9.--FSII refractometer.
The methods you will use to test F-44 are the same
4. Fill the graduated cylinder and the
ones we just described for F-76 fuels.
separator funnel about one-third full of the
test fuel. Swish the fuel around in both the
In addition to the tests you will perform on both F-
cylinder and the funnel to clear away any
76 4. and F-44 fuels, you must perform one other test
foreign material, then toss it out.
on F-44. In this test, you will check for fuel system
icing inhibitors (FSII). For this test, you will use the
5. Fill the graduated cylinder with exactly 160
FSII refractometer kit, as shown in figure 2-9. View A
mL of the fuel sample. (Make sure the
of figure 2-9 shows the components of the test kit and
drain cock on the separator funnel is
the 5. set up. Views B and C show front and side
closed.)
views of the refractometer.
6. Pour the fuel from the graduated cylinder
As the name implies, the refractometer uses light
into the separator funnel.
to 6. indicate inhibitor levels. You must handle the
refractometer with care. It is delicate and can be
7. Using the piston pipets or an eye dropper,
damaged easily. You can use either a fluorescent or
add exactly 2 mL of water from the
an incandescent light source, but the area in which
aluminum dish to the separator funnel.
you perform test, must be well lighted. To perform
Place the cap on the funnel.
the test use the following steps:
8. Shake the funnel for at least 3 minutes,
1. Set up the refractometer ring stand
then place it on the ring stand.
assembly, as shown in view A of figure 2-9.
9. Open the hinged plastic cover on the
2. Using a clean sample bottle, take a 1-quart
window of the refractometer. Make sure the
sample of the F-44 you will test.
window and cover are clean. Place several
drops of water on the window. Close the
3. Fill the aluminum dish that comes with the
cover and look through the eyepiece.
kit one-half full. (If the dish that comes
Observe the shadow line.
with the kit is damaged or missing, you can
use any clean dish.)