The online particle counter PAMAS S50P AVTUR is used as fixed installed measuring instrument for condition monitoring and contamination analysis of Aviation Turbine Fuel. More than just providing the triple code according to ISO 4406, PAMAS S50P AVTUR measures the particle number in eight different size channels and early alerts in case of failures caused by bigger particle sizes (e.g. corrosion). Using this online particle counter, the filling of contaminated Aviation Turbine Fuel into the tank can be prevented.