By now most field technicians have used meters to measure CO emissions for furnaces, water heaters, and other combustion appliances. When measuring CO emissions from a vented appliance, the metal probe is inserted into a hole drilled in the metal vent pipe. Measurement of CO emissions from a gas oven is performed using a similar technique.
However, rather than inserting the probe into a hole drilled in a vent pipe, the technician inserts it into the oven port that is usually located at the rear of the flat range top. A vacuum pump in the measurement device pulls combustion gases through the metal probe, into the plastic hose and the CO measurement cell, and finally expels the gases through an exhaust port.
Read all of Rick Karg's article, "C0 Testing for the Real World" in the January/February, 2002 issue of Home Energy magazine.