Provided, a trace gas measurement apparatus for electrical equipment that includes at least one sample cell configured to collect an oil sample from the electrical equipment. The sample cell includes (i) an oil receiving portion for receiving an oil sample, and (ii) a head space in an upper section thereof receiving ambient air therein, an oil pump for selectively pumping oil into and out of the sample cell, and a hydrogen gas sensor within an exhaust path of the sample cell. The hydrogen gas sensor receives the air exhausted from the sample cell and measures hydrogen gas present in the exhausted air.