Patent ID: 6978659

Claim:
A system for detecting when a fluid is leaking from a machine or from one or more connecting hoses providing and removing the fluid from the machine, the system comprising: a leak sensor apparatus ( 10 ) having two conductors ( 10 a–b ) held in spaced apart relation in a fluid-permeable insulating material ( 10 c ), responsive to an impressed voltage causing a voltage difference between the two conductors ( 10 a–b ), for providing a leak detection current when fluid from the machine leaks through the fluid-permeable membrane ( 10 c ); and a flow control device ( 16 ), for providing the impressed voltage, for stopping the flow of the fluid to the machine in response to the leak detection current; wherein the leak sensor apparatus ( 10 ) also includes a leak sensor detection component ( 10 d ) completing a circuit path for an alternating or radiofrequency current of a higher frequency than the leak detection current, and wherein the flow control device ( 16 ) is configured to provide an impressed voltage corresponding to the higher-frequency current and to detect the higher-frequency current in order to determine if the leak sensor apparatus ( 10 ) is coupled to the flow control device ( 16 ).