SAMPLE CONNECTION continued
The sampling connection may be located on the pipe before and after a filter vessel (filter separator or monitor) to allow you
to compare the readings to determine the performance of the filter in removing free water. Connections should be available
for obtaining Aqua-Glo test results all the way from the refinery to the aircraft refueling nozzle.
FLUSHING
Attach the empty test pad holder assembly to the quick disconnect coupler at the sample connection. Establish system
flow. Open the toggle valve by lifting the handle. Allow at least 1 liter of fluid to pass through the assembly into a collection
container. Opening and closing the valve several times will insure better flushing. Remove the assembly after flushing.
SPOILAGE OF WATER DETECTOR PADS
Aqua-Glo test pads are heat sealed in aluminized composite envelopes to ensure that moisture from the air will not reach
the pad. Pads that were stored for 8 years were still in good condition, but statistical studies have proven that up to 4 or
5% of the envelopes have enough water permeability to spoil the pads. This occurs in the first six months. A spoiled pad
is easily identified by its
yellow
color. The operator should inspect every pad before it is used. If it is not
orange
in color, it
must not be used.
TEST PROCEDURE
NOTE: An abbreviated test procedure may be found on last page of this manual.
Do not remove the test pad from the hermetically sealed package until ready to use. Do not touch the pad with fingers; use
the included pointed tweezers to handle the pad at all times. Do not allow any discrete water droplets to come into contact
with the pad (from rain, sneezing, coughing etc.). Exposure of the test pad to the atmosphere, especially on humid days, will
also ruin the pad in a matter of minutes.
Open the test pad holder assembly and insert a test pad in the outlet half using tweezers. Be sure that the orange colored
side of the pad is facing upstream (you can see the orange side with the pad in the holder). Run the test immediately.
Attach the test pad holder assembly to the quick disconnect. Open the toggle valve.
Pass 500 ml of fuel through the pad, accurately measuring the test sample quantity in the calibrated plastic bottle in the kit.
Normal sample volume is 500 ml of test fuel, but if the reading is off scale (on high side), a sample volume as small as 100
ml in volume may be used in a repeat test using a new pad, by applying a correction factor, as explained below. A small
graduated cylinder should be used to measure smaller sample volumes accurately. The reading must be adjusted to allow
for a smaller sample volume; see Calculation
on the next page.
RATING PROCEDURE
Remove the test pad from the holder using tweezers and press
between
dry paper blotters or absorbent towels to remove
excess fuel. Press firmly (about 5 lb. force) 3 or 4 times with heel of hand, moving the pad with tweezers each time.
For maximum accuracy, the test pad should be read within 3-5 minutes after sampling is initiated. If the test pad is not read
immediately after sampling, it must be placed in a desiccator to prevent moisture pick up from the air. However, readings
made on dried test pads, that is, not damp with fuel, should be avoided if possible since they will give high and erroneous
results. Conversely, rating a pad which has not been well blotted will give a low reading as the excess fuel will absorb part
of the ultraviolet light and decrease fluorescence.
The ultraviolet light must be on to get a reading. This can be verified when the switch is turned on. The center of the
white
indicator button
will glow a light green if the ultraviolet tube is operating. In bright sunlight, you may have to cup your hand
over the indicator to see that the button is glowing.
Turn off the instrument light immediately after use to conserve battery power. If the pointer will not go all the way to the zero
(center). Move the lever until the pointer is as close to the center as possible. If the lever is below the 1 mark, your fuel has
less than 1 ppm of water. If the lever is at the 12 end of the scale, you have more than 12 ppm.
Record the instrument reading where the lever crosses the scale (estimated to the nearest tenth). Record the sample
volume and the fuel temperature at the time of the test. See section titled “Comments.”
Visual observation of the used test pad is often of value. This is easily accomplished by removing the photocell comparator
assembly and viewing the test pad through the rectangular window on the side of the instrument in a darkened room with
the ultraviolet light turned on. Free water in fuel is normally well dispersed and will form an even distribution of many small
points of yellow fluorescence on the test pad when illuminated.
Large water drops, however, will form a few large spots of yellow fluorescence on the pad. These large spots usually are
indicative of a separator element failure, rather than a coalescer element failure if the test is performed downstream of a
filter separator.
