EXPLANATION
This test method provides a rapid, portable means to measure the presence of surfactants in aviation turbine fuels using a portable separatometer. The instrument has a measurement range of 50 to 100. There are two modes of operation of the instrument. The primary difference between them is the rate of fuel flow through the fiberglass coalescing material. The lapsed time required to force the emulsion through the coalescer cell is 45 s for Mode A and 25 s for Mode B. Selection of Mode A or B depends upon the specific fuel and specification requirements.
TEST SUMMARY
A water-fuel sample emulsion is created in a syringe using a high-speed mixer. The emulsion is then expelled from the syringe at a programmed rate through a standard fiberglass coalescer and the effluent is analyzed for un-coalesced water by a light transmission measurement. The results are reported on a 0 to 100 scale to the nearest whole number. High numbers indicate the water is easily coalesced, implying that the fuel is relatively free of surfactants. A test can be performed in 5 to 10 min.
TEST PRECISION
See the precision of different fuel types in figures below.
This test method has no bias.