A gas trap includes a sample enclosure, a bubbler enclosure, an agitator, and a brushless, DC motor. The sample enclosure has a liquid inlet, a gas sample outlet, and a sample enclosure wall with a sample enclosure wall portion and a shared wall portion. The bubbler enclosure has a bubbler air inlet, a bubbler air outlet, and a bubbler enclosure wall with a bubbler enclosure wall portion and the shared wall portion. The sample and bubbler enclosures are fluidly coupled through the shared wall portion so that sufficiently pressurized bubbler air entering through the bubbler air inlet maintains the drilling fluid in the sample enclosure at a level determined by the location of the bubbler air outlet when the liquid inlet and the bubbler air outlet are both submerged in the drilling fluid.