Apparatus for producing standard gas mixtures

An apparatus for producing standard gas mixtures, comprising:

• a) a plurality of gas sources, comprising a source of raw gas and sources of different high-concentration standard gases;
• b) a manifold for gathering the high-concentration standard gases from the sources of high-concentration standard gases and delivering a high-concentration standard gas mixture;
• c) a source of sample gas;
• d) a sample gas passage connected to said source of the sample gas;
• e) means for controlling the pressure of the raw gas;
• f) means for controlling the pressure of the sample gas;
• g) purifying means for purifying the raw gas supplied from the source of raw gas, thereby generating a high purity diluent gas;
• h) means for dividing said-high purity diluent gas into first and second portions, said second portion flowing through first restricting means;
• i) mixing means for mixing the first portion of the high-purity diluent gas with the high-concentration standard gas mixture supplied from said manifold, to generate a substantially homogeneous medium-concentration gas mixture;
• j) means for dividing the medium-concentration gas mixture into a first flow and a second flow, said first flow being supplied through second restricting means;
• k) means for controlling the flow rate of the second portion of the high purity diluent gas;
• l) means for controlling the flow rate of the sample gas;
• m) a third restricting means for selectively receiving the second portion of the high purity diluent gas, the sample gas, or both and generating a diluent gas;
• n) means for mixing the first flow of said medium-concentration gas mixture and the diluent gas for generating gas for generating standard low-concentration gas mixture;
• o) means for controlling the pressure of the second flow of said-medium concentration gas mixtures;
• and
• p) means for controlling the pressure of said low-concentration gas mixture.