The term Integration Time is used for Radio Telescopes and CCDs, but I'm not sure what it means. Sometimes it is used as the length of time data is collected, i.e., 20 seconds of integration time means an object was observed for 20 seconds.
It can mean more specifically the time over which an analog signal is converted into a digital count representing an integration of the signal. The integration time may be chosen to avoid systematic noise or random noise. For some objects, favorable (i.e., sufficiently long) integration times can be calculated from the temperatures of the observed object and the observing instrument.