time period in which no data are acquired.

Wait time can happen for multiple reasons. For example, the time period until a detector is ready (e.g. EDS detector is cooled down). The time period until the specimen has reached the desired state for a measurement (e.g. in-situ heating/cooling). The time period until the machine has reached the desired state (e.g. switching from high vacuum to low vacuum mode in a variable pressure SEM). Frame flyback time may also be considered a wait time.