A pump for ultra-pure fluids comprises a flexible diaphragm separating a fluid chamber from an air chamber. The diaphragm creates an airtight seal between the fluid chamber and the air chamber. Any leak from the fluid chamber into the air chamber is detected by a fiber optic system comprising an element and two optical fibers that are disposed such that light is detected by the second optical fiber only when the element is not in contact with liquid. A second fiber optic system can also be used to determine the stroke of an oscillating member by disposing the fiber optic lines at an angle calculated to reflect light off of the oscillating member when the member arrives at a predetermined location. The fiber optics are adapted to be resistant to corrosion, non-igniting, and non-contaminating.
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation-in-part of U.S. patent application Ser. No. 09/946,752, filed Sep. 4, 2001 now U.S. Pat. No. 6,402,486, entitled "Fiber Optics System for Detecting Pump Cycles", which is a continuation of U.S. patent application Ser. No. 09/642,426, filed Aug. 21, 2000, now abandoned, entitled "Free-Diaphragm Pump", which is a continuation of U.S. patent application Ser. No. 09/166,490, filed Oct. 5, 1998, entitled "Free-Diaphragm Pump", now issued as U.S. Pat. No. 6,106,246. The foregoing patents and patent applications are incorporated herein by reference.
A fiber optic system for detecting a stroke of a pump, the fiber optic system including a first fiber optic line configured for directing light onto a portion of the pump that moves during the stroke of the pump. The system further includes a second fiber optic line configured for receiving light that has been transmitted from the first fiber optic line and reflected by the portion of the pump, wherein receipt of the light by the second fiber optic line occurs at a specified point during the stroke of the pump. The moving portion of the pump may be the diaphragm, the reciprocating portion, or any other part of the pump that cycles at regular intervals as the pump operates.
