1. Cleanliness analysis -  Methods

In automotive sector an increasing number of  components contains specifications for cleanliness in product drawings.

Methods used for evaluating cleanliness levels (extracting, analysing and expressing results) are covered by the standard ISO 16232.

Examples of function-relevant automobile parts:
Motor and powertrain components (valves, camshaft, crankshaft, gear wheels etc.)
Hydraulic components (ABS, ESP, power-steering etc.)
Fuel supply (valves, hoses, elements of hose pipes)
Electronic construction units. 

The method:

When determing the remaining pollution of components (i.e. components passed their standard cleaning) sample parts are picked out and cleaned again in a defined way. The method of cleaning (e.g. ultrasonic bath, rinsing), the cleaning fluid (e.g. water, alcohol), the amount of cleaning fluid and other parameters are part of the production process and subject to specifications. The cleaning fluid will then be passed through a filter membrane which held back the residue particles. Here also the membrane type (Cellulose, Teflon, Polyester net) have influence on the number and sizes of captured particles. After this process the filter is dried.

Method of determining technical cleanliness: