COSA Xentaur SF6 Purity Pro - Manual (Page 20)

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8. Definition of Terms
vol%: The rate of substance occupying in some volume. The unit is indicated by percentage.
ppm: The rate of substance occupying a given volume. The unit is indicated by ppm, or “parts per
million.”
%LEL: This is the unit when defining he Lower Explosive Limit of a combustible gas as 100%.
mg/l: This is the unit of the target gas mass that is contained in one liter. The standard is under the
condition of 20ºC, 101.3 kPa.
MJ/m3 Gross: This is the unit of calorie, and it is indicated by gross calorific value 0ºC. Gross
calorific value 0ºC is a common calorie unit among city gas companies. It is equal to the calorie in
case of complete combustion of a gas 1m^3 under the standard condition (0ºC, 1 pressure.) Gas
combustion generates steam. Gross calorific value includes the calorie of the steam (latent heat.)
MJ/m3 Net: This is the unit of calorie, and it is indicated by net calorific value 0ºC. net calorific
value 0ºC is equal to the calorie incase of complete combustion of a gas 1m^3 under the standard
condition (0ºC, 1 pressure.) Gas combustion generates steam. Net calorific value excluded the
calorie of the steam (latent heat.)
*Gross calorific value = Net calorific value + Latent heat
Measuring Gas: The target gas to measure in the sample gas.
Base Gas: The balance gas in the sample gas.
Reference Gas: The gas (fresh air)to take the standard reflection ratio.
Gas Chamber: chamber that is filled by sample gas.
Reference Gas Chamber: Chamber that is filled by reference gas.
AIR CAL VALUE: Concentration indicated on the display when AIR CAL key is pressed.