Equipment Used to Measure Nitrogen Oxide
- A five-gas analyzer measures nitrogen oxide gases, as well as hydrocarbons, carbon dioxide, carbon monoxide and oxygen released by a car's engine through the gas pipe exhaust. A portable instrument that uses either AC or DC current, the analyzer tests nitrogen oxide emission in a mechanic's garage or at home. The analyzer connects to the exhaust pipe of a running car -- and the car's battery, if using a DC-powered analyzer. Testing while the car moves will determine the engine's emission level.
- A dynamometer -- an electronic device with two rollers -- works with a five-gas analyzer to measure nitrogen oxide emissions. The devise simulates a moving vehicle by electronically applying various speeds and load to it, as vehicles usually emit nitrogen oxide when carrying a load. After the vehicle drives over the dynamometer rollers, the nitrogen oxide emission level appears on the five-gas analyzer.
- Most cars manufactured since 1996 contain an on-board computerized diagnostic system that scans vehicle subsystems, such as the exhaust sensors. This diagnostic system assesses the volume of emissions the car releases to the atmosphere. Hand-held scanning tools also exist.
- Invisible gasoline fumes containing nitrogenous gases easily evaporate into the atmosphere from leaks around the fuel tank's seals. A gas-cap tester -- a pressurized gauge that connects to an open, uncovered gas cap -- can determine such leaks. When the tester applies pressure, the cap's inability to maintain the pressure indicates that it allows nitrogen oxide to pass through. According to the Mid-America Regional Council, which holds emissions clinics and gas-cap testing, replacing a leaky cap can save as much as one gallon of gas every 15 days, and only costs about $20.