Abstract: An infrared leak detector for detecting gas leaks in a pressurized gas source includes a housing that contains a sampling chamber, an infrared emitter for emitting IR energy, a filter that allows IR energy in the range of approximately 7 to approximately 14 microns to pass therethrough, a sensor that detects IR energy that has passed through the single filter to detect the presence of selected gas constituents in the gas sample, and a pump arranged to force a gas sample from a suspected gas leak that emanates from the pressurized gas source though the sampling chamber.