Gas analyzers and units "ppm"
Gaz analyzer - it is a measuring device for determination of high-quality and quantitative composition of mixtures of gases. Distinguish the gas analyzers of hand action and automatic. Among the first absorbings econometers in which components of gas mixture is consistently taken in different reagents are most widespread. Automatic gas analyzers measure some physical or physical and chemical parameter of gas mixture or its separate components continuously.
ppm (millionth stake) - a metage concentration, and other relative sizes, is analogical on sense a percent or promille. Designated reduction of "ppm" (from angl. of "Parts per million", pi-pi-em is read, «parts on million»).
1 ppm = 0,001 ‰ = 0,0001 % = 0,000001 = 10-6
For example, if it is indicated that the mass stake of matter in mixture makes 15 ppm, it means that there are 15 mgs of this matter on every kilogram of mixture (or 15 gramme on a 1 ton).
If the question is about by volume concentrations (by volume stakes, stakes on volume), 1 ppm is a cube centimetre (it is a milliliter) on a cu.m. (cm3/m3). So, the concentration of carbon dioxide (CO2) in the atmosphere of Earth about 380 ppm, and it means that in every cubic meter of air 380 ml (about 2 glasses) is occupied by carbon dioxide.
Often the mg of matter is resulted to 1 m3 of gas at normal terms ppm name also. It right only partly, because mass of 1 m3 air is practically equal to 1 kg But it quite unright, if this determination is extended on the cubic meter of arbitrary gas. Also unright to count ppm equal mgs on a litre, that partly right for water solutions, but gives a large error in transition to hydrocarbons the density of which is 0,5-1 kg/l.