Systems and methods are described to determine whether a sample transmitted through a transfer line from a remote sampling system contains a suitable sample to analyze by an analysis system. A system embodiment includes, but is not limited to, a sample receiving line configured to receive a liquid segment a first detector configured to detect the liquid segment at a first location in the sample receiving line; a second detector configured to detect the liquid segment at a second location in the sample receiving line downstream from the first location; and a controller configured to register a continuous liquid segment in the sample receiving line when the first detector and the second detector match detection states prior to the controller registering a change of state of the first detector.