There are three reasons why the measurement signal may be in hold. All three result in the same behavior, but they also interact with each other.
Wash-related hold, see Hold during wash, and external hold, see External hold, are connected in parallel. If at least one of them is active, the measurement result will be in hold.
Tolerance time, see Tolerance time, is independent of these two, but the tolerance time is reset whenever there is another reason for the measurement hold. For example, if the tolerance time is set to 10 s, and wash hold becomes active after 7 s, the remaining tolerance time resets to 10 s After the wash is over, there is still 10 s of tolerance time remaining.