Leak-detection system

Claim 2

A leak-detection system for detecting leakage of a tracer gas from a container comprising: a. an enclosure for the container forming an accumulator for sample gas, b. a sensor responsive to flow of the tracer gas therethrough for producing an output signal variable in accordance with the concentration of said tracer gas, c. a sample gas conduit having an inlet coupled to said accumulator and an outlet coupled to said sensor, d. control means for controlling the flow of sample gas from said accumulator to said sensor through said conduit, e. means actuating said control means to initiate a flow of sample gas through said conduit to said sensor, f. and means responsive to a predetermined output signal level from said sensor below a saturation level for actuating said control means to stop the flow of sample gas through said conduit to said sensor to prevent saturation of said sensor.

Claim 3

A leak-detection system as recited in claim 1 including leak-indicating means actuated by said sensor when its signal output reaches said predetermined level.

Claim 4

A leak detector system as recited in claim 1 wherein the control means comprises: a. means for pumping gas through said sample gas conduit to the sensor at a constant pumping rate, b. and means for supplying a purging gas to the inlet of the sample gas conduit at a rate greater than said constant pumping rate so as to preclude flow of sample gas from said accumulator to said sensor.

Claim 5

A leak detection system as recited in claim 1 wherein the control means comprises: a. a source of purging gas free of said tracer gas, b. a purging gas conduit coupling said source to the sample gas conduit, and c. valve means for controlling the flow of purging gas through said purging gas conduit.

Claim 6

A leak-detection system as recited in claim 1 wherein the control means comprises: a. a source of purging gas free of said tracer gas, b. a first purging gas conduit controlled by a first valve coupling said source to the inlet of the sample gas conduit, c. a second purging gas conduit controlled by a second valve for coupling said source to the outlet end of the sample gas conduit, d. an exhaust vent coupled to the sample gas conduit between the inlet and outlet ends controlled by a third valve, e. a signal responsive means for jointly operating said first, second and third valves.

Claim 7

A leak-detection system for detecting leakage of a tracer gas from a container comprising: a. an enclosure for the container forming a gas accumulator, b. a sensor responsive to flow of said tracer gas therethrough and producing an output signal in response thereto, the calibration of said sensor being sensitive to changes in gas flow rate therethrough, c. a sample gas conduit having an inlet coupled to said accumulator and an outlet coupled to said sensor, d. an enclosure forming a sample gas chamber connected to said sample gas conduit between the inlet and outlet ends thereof, said chamber having a vent, e. a first pumping means for pumping gas from said sample chamber through said sample gas conduit to said sensor at a constant rate, f. a second pumping means for pumping gas to the sample chamber from the inlet of the sample gas conduit at a pumping rate greater than the pumping rate of the first pumping means, excess gas leaving said sample chamber through said vent, g. means comprising a purging gas conduit controlled by a valve for supplying a purging gas to the inlet of said sample gas conduit at a rate greater than the pumping rate of the second pumping means whereby purging gas is pumped to the sensor with excess entering the accumulator when said valve is open and sample gas is pumped frOm said accumulator to said sensor when said valve is closed, and h. means for operating said valve to control the flow of purging gas and sample gas to said sensor, the gas flow rate and hence the calibration of said sensor being unaffected by the operation of said valve.

Claim 8

A leak-detection system for detecting leakage of a tracer gas from a container comprising: a. an enclosure for the container forming a gas accumulator, b. a sensor responsive to flow of said tracer gas therethrough and producing an output signal in response thereto, the calibration of said sensor being sensitive to changes in gas flow rate therethrough, c. a sample gas conduit having an inlet coupled to said accumulator and an outlet coupled to said sensor, d. an enclosure forming a sample gas chamber connected to said sample gas conduit between the inlet and outlet ends thereof, said chamber having a vent, e. a first pumping means for pumping gas from said sample chamber through said sample gas conduit to said sensor at a constant rate, f. a second pumping means for pumping gas to the sample chamber from the inlet of the sample gas conduit at a pumping rate greater than the pumping rate of the first pumping means, excess gas leaving said sample chamber through said vent, g. means comprising a purging gas conduit controlled by a valve for supplying a purging gas to the inlet of said sample gas conduit at a rate greater than the pumping rate of the second pumping means whereby purging gas is pumped to the sensor with excess entering the accumulator when said valve is open and sample gas is pumped frOm said accumulator to said sensor when said valve is closed, and h. means for operating said valve to control the flow of purging gas and sample gas to said sensor, the gas flow rate and hence the calibration of said sensor being unaffected by the operation of said valve.

Claim 9

A leak-detection system as recited in claim 6 including: a. means for closing the valve to pump sample gas from the accumulator to the sensor, and b. control means responsive to an output signal from the sensor for automatically opening the valve when leakage of the tracer gas from the container into the accumulator is detected by the sensor.

Claim 10

A leak-detection system as recited in claim 7 including leak-indicating means which is also actuated by the output signal from the sensor.

Claim 11

A leak-detection system as recited in claim 6 including: a. a second purging gas conduit controlled by a valve for supplying purging gas to the outlet of the sample gas conduit, b. an exhaust vent controlled by an exhaust valve coupled to said sample gas conduit between the first pumping means and the outlet end, and c. means for operating the purging gas valves and the exhaust valve jointly to purge tracer gas from the sample gas conduit.

Claim 12

A leak-detection system comprising: a. an accumulator adapted to enclose a container to be leak tested, b. a sensor for detecting gas leaking from the container, c. a sample gas conduit coupling said accumulator to said sensor, d. pumping means for pumping gas through said sample gas conduit to said sensor at a constant pumping rate, e. means including a purging gas conduit controlled by a valve for supplying purging gas to the inlet of said sample gas conduit at a rate greater than said pumping rate, f. means including said last-mentioned means for pumping the purging gas to the sensor with excess entering the accumulator when the valve is open and for pumping the sample gas from the accumulator to the sensor by the pumping means when the valve is closed.

Claim 13

A leak-detection system comprising: a. an accumulator adapted to enclose a container to be leak tested, b. a sensor for detecting gas leaking from the container, c. a sample gas conduit coupling said accumulator to said sensor, d. pumping means for pumping gas through said sample gas conduit to said sensor at a constant pumping rate, e. means including a purging gas conduit controlled by a valve for supplying purging gas to the inlet of said sample gas conduit at a rate greater than said pumping rate, f. means including said last-mentioned means for pumping the purging gas to the sensor with excess entering the accumulator when the valve is open and for pumping the sample gas from the accumulator to the sensor by the pumping means when the valve is closed.