5.1 This practice is suitable for the removal of contaminants found on materials, parts, and components used in systems requiring a high level of cleanliness, such as oxygen. Parts shall have been precleaned to remove visible contaminants prior to using this procedure. Softgoods such as seals and valve seats may be cleaned without precleaning.

5.2 This procedure may also be used as the cleanliness verification technique for coupons used during cleaning effectiveness tests as in Test Method G122.

5.3 The cleaning efficiency has been shown to vary with the frequency and power density of the ultrasonic unit. Low frequencies in the 20 to 25 kilohertz range have been found to damage soft metals such as aluminum and silver. Therefore, the specifications of the unit and the frequencies available must be considered in order to optimize the cleaning conditions without damaging the parts.