INDICATOR ELEMENT Russian patent published in 2006 - IPC G01N31/22 G01N33/22 

FIELD: analytical methods in petroleum industry.

SUBSTANCE: invention relates to determining content of water and suspended impurities in aviation fuel and petroleum products, e.g. kerosene and aviation oils. Indicator element used in analytical procedures includes two layers of polymeric porous hydrophobic mixture with ultra-thin fiber structure, first one being impregnated with ferric sulfate solution. Both layers are impregnated with solutions based on the same solvent containing distilled water and ethyl cellosolve, dried, and attached to each other. Structure of ultra-thin fibers has specific packing density from 0.013 to 0.066 kg/m²·mm Hg. First layer is impregnated with 6-9% ferric sulfate solution and second one with solution containing potassium ferricyanide and potassium ferrocyanide at their ratio 1:(25-35) in that layer. Solvent, in particular, contains 40-60 vol % distilled water, 30-50 vol % ethanol, and 5-15 vol % ethyl cellosolve.

EFFECT: accelerated indication and increased analytic accuracy at lower usage of porous base.

1 tbl