Parts Per Million.
High Hydrocarbon (HC) emissions are almost always a sign of poor fuel ignition. Hydrocarbons are basically raw fuel. PPM (parts-per-million) is a way of quantifying small concentrations.
In measuring exhaust emissions.
Indolene is a form of gasoline used in testing because it is standardized and has no additives. Indolene gasoline is used for the US Federal Test Procedure (FTP) to certify vehicles for emissions rather than commercial gasoline. Indolene fuel used in certification typically has a sulfur content below 50 parts per million (ppm). On the other hand, commercial gasoline sulfur content ranges between 30 and 1000 ppm throughout the US with an average of about 300+/-50 ppm. Indolene gasoline results in reproducible tailpipe emissions from a test vehicle. Commercial gasoline results in a wide range of emissions. The emissions differences are attributable largely to the disparity in gasoline sulfur content. source: http://www.meca.org/galleries/default-file/sulfur.pdf http://www.futurefueltechnologies.com/?page_id=42
ppm means Parts per million
ppm stands for parts per minute.
In 2003 carbon dioxide emissions were 370 ppm (parts per million). This year (2013) they reached 400 ppm. At the beginning of the Industrial Revolution they had been 280 ppm for thousands of years.
2 ppm means 2 parts per million.
ppm stands for "parts per million" and it is the amount of one substance in another substance. You would test for it using a test kit appropriate for whatever chemical level you are trying to determine, such as a chlorine test kit or a calcium hardness test kit.
Answering "How do you fix a 1995 Chevrolet Lumina emission test fail NO x ppm reading fail?"
PPM in diesel refers to "parts per million" and typically represents the concentration of sulfur compounds in the fuel. The lower the PPM value, the cleaner the diesel fuel and the environment. Regulations often set limits on the sulfur content in diesel fuel to reduce emissions and environmental impact.
I had the same problem with my 92 Prizm. NO ppm was 4350. I replaced the EGR Modulator and it solved the problem.
Carbon dioxide levels are not decreasing in the atmosphere, in fact, they are increasing. In 1960 levels were 316 ppm. In 1970 levels were 325 ppm. In 1980 levels were 338 ppm. In 1990 levels were 353 ppm. In 2000 levels were 369 ppm. In 2010 levels were 388 ppm. Jan of 2012 levels were 393.09 ppm. As of today we are at 393.68 ppm at Manua Loa.