Decay curve

Representation of the decay curve determines whether the selected method and the appropriate parameters are suitable for extraction of the contamination particles.

For determing the decay curve an adequate number of components is necessary.

Cycle of the determing of a decay curve

  • appropriate extraction conditions and number of components is to appoint
  • blank value is to investigate
  • extraction with the appointed parameters and components is to reiterate
  • for each extraction the chosen parameters and amount of fluid and / or testing period has to keep exactly
  • cleanliness value of the cleanliness fluid has to be investigated


  • cleanliness value of the last extraction has to be devided through the sum of all cleanliness values which have been done already
  • criteria for decay curve: the relation has to be ≤ 10% 
  • if criteria is > 10% a further extraction is necessary
  • if the criteria is not reached within six extractions, the parameters of the extraction have to be changed and a new decay curve has to be determined