The 327 is a hand held combustion analyzer for easy and accurate set up and maintenance of all types of residential and commercial combustion systems. The multipurpose 327 does flue gas tests, efficiency analysis, carbon monoxide safety checks in stack in ambient air, fuel pressure set up, as well as draft/differential pressure analysis and differential temperature testing. The 327 has a rugged single line probe with fast and easy connection. It has durable sensors that are easy for the user to replace. Cleary worded menus, not codes, guide the technician. The powerful magnets hold the analyzer on equipment surfaces and allow for fast and convenient print out on the IR printer. The brightly backlit four-line display may be configured to show readouts in any order desired. The sensors are easily replaced in the field so there is no need to send it back to the factory, minimizing the downtime of the unit.