The purpose of this part of ISO 16232 is to determine the mass of particulate contamination by gravimetric analysis. Contaminants are separated from the extraction liquid by filtration. It applies to automotive components in contact with a fluid. Unless otherwise specified, this part of ISO 16232 deals with particulate cleanliness only. It does not, therefore, cover appearance defects or contamination by liquid or gaseous materials. It covers the amount of residual particulate contaminants resulting from manufacturing processes and from the environment.