The time required for a cleanroom, after being contaminated, to recover to the stable, specified indoor cleanliness class.

[Reference] For a cleanroom during the operation of the purification air-conditioning system, the time required for the indoor dust concentration to decrease from a relatively high value to a stable value is defined as the self-cleaning time (min). It is related to the indoor air change rate and the air distribution.

[Reference] If this process occurs during the start-up phase of the purification air-conditioning system, it is called the start-up self-cleaning time. If this process occurs during the normal operation of the purification air-conditioning system, the time required for the cleanroom, after being contaminated, to recover to the stable, specified indoor cleanliness class is called the contamination self-cleaning time.

[Reference] Here it specifically refers to the time required for a clean operating room, under the specified air change rate, to recover from the lower cleanliness class after contamination (for example, after the previous operation) to the specified high at-rest cleanliness class (for example, the class required before the next operation begins); this is called the post-operation contamination self-cleaning time. It should not exceed the time required for successive operations.