courtesy of Pamas
Fuel is less viscous than oil. In low viscous fluids, the particles settle in the liquid and form a sediment at the bottom of the bottle (sedimentation). Individual particles might also stick together during storage and become agglomerated. Before a sample can be analysed with a laboratory measurement instruments, it needs to be prepared to redisperse the particles in the liquid.
Before undertaking laboratory particle analyses, the sample should be adequately prepared for measurement. In case of online measurement, sample preparation is not possible, as the liquid is directly taken in its original physical state during operation. To avoid phenomena of sedimentation and agglomeration during measurement, particle counters for fuel analysis are equipped with special features, adapting them for the specific requirements of fuel condition monitoring.
For Jetfuel analysis, PAMAS has developed the portable particle counter PAMAS S40 AVTUR which can be used both for online and batch sampling. The system is compliant with the IP 577 analysing method of the Energy Institute London and to the DEF STAN 91-91 standard of the British Ministry of Defence.
Fuel containing free water can be analysed with the PAMAS S50DP online particle counter. This instrument is equipped with an integrated dilution system which continuously adds a programmable amount of a low viscous solvent to the raw sample fluid before online measurement. Without prior dilution, free standing water in fuel would lead to false measurements. In the PAMAS S50DP, the water droplets in the fuel sample are dispersed in the added solvent and thus are not detected as particles during the subsequent online measurement.