Multi-channel monitoring of rotating cleaning springs, used for cleaning passageways of e.g. a CVD unit in IC manufacture, comprises alarm signal emission on receiving spring breakage signals from a timed trigger signal register

摘要

Multi-channel monitoring of rotating cleaning springs comprises emitting an alarm signal if an alarm (9) receives two or more spring breakage signals from a timed trigger signal register (5,6). Multi-channel monitoring of one or more rotating cleaning springs, for cleaning the inner wall of a narrow passageway between two compartments, is carried out using a monitoring device which is provided at each spring end and which comprises: (a) a signal generator fitted at one spring end; (b) a signal trigger (1,2) which is triggered by the signal generator at least once during each revolution of the spring and which has an output (11,12) for emitting a passage signal when the signal trigger is triggered by the signal generator; (c) a timer (7,8) with an input (21,22) for input of a start signal for starting measurement of a predetermined completion time and an output (23,24) for emitting a completion signal after expiry of the predetermined completion time; and (d) a register (5,6) which has an input (13,14) for receiving the passage signal from the signal trigger, an input (17,18) for receiving the completion time from the timer and an output (19,20) for delivering a spring breakage signal depending on whether, after receiving a passage signal and before receiving a new passage signal, a completion signal has been received. All the monitoring devices have a common alarm (9) with a system for emitting an alarm signal if its inputs (25, 26) receive two or more spring breakage signals. An Independent claim is also included for a method of monitoring a rotating cleaning spring using equipment as described above.