An oxygen gas analyzing device in which gas sampled from a flue is analyzed without the need of an external driving source. A sampling tube protrudes into a flue through a wall thereof. A partition board divides the gas sampling tube extending from the protruding end of the tube forming gas flow-in and...http://www.google.com/patents/US4339318?utm_source=gb-gplus-sharePatent US4339318 - Oxygen gas analyzing device
