ASTM D7619 is a light obscuration test method that uses laser light beams passing through a fuel sample to determine the size and number of particles that block filters and may damage engines.
The light-blocking particles create a shadow that is captured by a computer-controlled light sensor; the total amount of particles as well as their specific sizes are measured.
The test method is quite accurate and is non-discriminatory. As it is a purely calculative test, it does not determine the composition of the particulate pollutants. It is designed to measure all particles of 4-, 6-, and 14-microns that can clog fuel filters or damage engines, including inorganic matter such as dust, catalyst fines, rust, and dirt, as well as organic matter; including gums, microbial matter, along with suspended water droplets.
Test | Units | Neat aged diesel | XBEE aged diesel | Difference |
|---|---|---|---|---|
>= 4 µm | counts/ml | 9,339 | 7,022 | -24.81% |
>= 6 µm | counts/ml | 2,280 | 1,608 | -29.47% |
>= 14 µm | counts/ml | 141 | 75 | -46.81% |
XBEE diesel fuel additive does not affect inorganic particulates, but it does break down and reduce the size and quantity of sticky organic particles, which can quickly clog fuel filters, shortening their life. If left untreated, water in the fuel can erode metal parts and destroy injector tips. Water also displaces the lubrication layers of engine oil and fuel, causing accelerated wear of moving parts. XBEE reduces the size of water droplets to microscopic levels, allowing them to pass safely through the fuel system and vaporize harmlessly during combustion.
