A photoacoustic (PA) leak detector on the base of a compact CO2 laser is proposed for the detection of hydrogen leaks from cooling systems of electric power generators. Leak detection is based on a trace gas marker SF6 registration, which is added to the gas carrier within the leakage area. Experimental results of SF6 impurity detection in weak gas leakage using a PA detector with a differential ring cavity flow type are sited. The threshold sensitivity of the detector is measured at 7.51010cm1. The effect of gas-flow rate through the detector is studied. The minimum reliably detectable flow is estimated to be 11010Pam3s, which exceeds the sensitivity of commercial helium and halogen leak detectors. Description and specifications of the developed model of a portable laser leak detector, designed in accordance with experimental results, are given.