Lag Depth Alarm signals the moment when drilling fluid coming from depth of interest reaches the surface. For regular mud sampling this alarm is repeated every certain interval, e.g. 5 m.

Dialog box with Lag depth alarm settings is invoked from the Lag Depth menu. When current Lag Depth reaches the alarm value, the acoustic signal will be triggered and the dialog box reappears.

Accepting the alarm with OK button will switch the alarm value to the next sample.