Patent ID: 8738306

Claim:
A method comprising: providing a translatable carriage having at least one carriage-mounted light-emitter, the carriage disposed about a fluid conduit, the fluid conduit extending from a manifold; inserting a bubble into a fluid of the fluid conduit, the fluid having a flow rate and a direction of flow within the fluid conduit; testing for at least one of: a leading edge and a trailing edge of the bubble, the testing based on a change in received light from the carriage-mounted light-emitter; if the at least one of: a leading edge and a trailing edge of the bubble, is detected, then (a) determining a first carriage position via the carriage-mounted light-emitter, and (b) advancing the carriage in the direction of flow to a carriage stopping position, returning the carriage in a reverse direction of flow from the stopping position toward the first carriage position; testing for at least one of: a leading edge and a trailing edge of the bubble, the testing based on a change in received light from the carriage-mounted light-emitter; if the at least one of: a leading edge and a trailing edge of the bubble, is detected, then (a) determining a second carriage position, and (b) invoking a tracking mode based on a difference between the second carriage position, the first carriage position, and the carriage stopping position; and if the at least one of: a leading edge and a trailing edge of the bubble, is not detected, then invoking a first tracking mode.