Abstract: A system for detecting gas leaks in a gas-containing component includes: a test gas comprising molecular hydrogen introduced on one side of a gas-containing component; a vacuum pump to collect a gas sample from the other side of the gas-containing component; a hydrogen detector to receive the gas sample and determine the hydrogen content therein; and, a trap containing a regenerable sorbent material upstream from the hydrogen detector, the sorbent material characterized by having less affinity for molecular hydrogen than for heavier hydrogen-containing molecular species. Regeneration of the sorbent may be accomplished by exposure to purge gas, or by exposure to a lower total pressure than existed during the test cycle.

Abstract: A leak detector contains a pump that withdraws gas from a volume into which a tracer gas is leaking. The volume may also contain small amounts of air or other gas in addition to the tracer gas. Downstream from the pump, a flow restriction creates a back pressure between this restriction and the outlet of the pump, the back pressure being determined by the pressure in the test volume, the pumping speed, and the nature of the flow restriction. The flow restriction may be fixed, such as an orifice or a section of a capillary tube, or it may be variable, such as a needle valve. In many cases, the back pressure may be adjusted to approximately one atmosphere, allowing the use there of various conventional gas sensors that are designed to operate at one atmosphere. The invention may also be used for general gas analysis problems.

Abstract: A leak detector contains a pump that withdraws gas from a volume into which a tracer gas is leaking. The volume may also contain small amounts of air or other gas in addition to the tracer gas. Downstream from the pump, a flow restriction creates a back pressure between this restriction and the outlet of the pump, the back pressure being determined by the pressure in the test volume, the pumping speed, and the nature of the flow restriction. The flow restriction may be fixed, such as an orifice or a section of a capillary tube, or it may be variable, such as a needle valve. In many cases, the back pressure may be adjusted to approximately one atmosphere, allowing the use there of various conventional gas sensors that are designed to operate at one atmosphere. The invention may also be used for general gas analysis problems.