Floating substrate monitoring and control device, and method for the same

An apparatus (100), comprising:

• a process tunnel (102), extending in a longitudinal direction (T) and bounded by at least a first and a second wall (120, 130), said walls being mutually parallel and spaced apart so as to allow a substantially flat substrate (140), oriented parallel to the walls, to be accommodated there between, and
• a plurality of gas injection channels (122, 132), provided in both the first and the second walls, wherein the gas injection channels (122) in the first wall (120) are configured to provide for a first gas bearing (124), while the gas injection channels (132) in the second wall (130) are configured to provide for a second gas bearing (134), said gas bearings being configured to floatingly support and accommodate said substrate (140) there between, characterized in that
• the first and/or second walls (120, 130) of the process tunnel are fitted with at least one substrate detection sensor (S′) at a respective substrate detection sensor location, said substrate detection sensor being configured to generate a reference signal reflecting a presence of a substrate between said first and second walls near and/or at said substrate detection sensor location;
• and in that the apparatus further comprises:
• a monitoring and control unit (160) that is operably connected to the at least one substrate detection sensor (S′), and that is configured to record said reference signal as a function of time and to process said reference signal.