Critical orifice dilution system and method

A gas dilution system comprising:

• first and second gas storage means, said first gas storage means containing a pressurized standard gas and said second gas storage means containing a pressurized dilution gas;
• first and second conduit means for conducting gas from said first and second gas storage means, respectively;
• at least one sensor means for measuring the pressure of gas in at least one of said first and second conduit means;
• first and second orifices communicating with said first and second conduit means, respectively, each capable of conducting pressurized gas therethrough at constant velocity;
• and
• mixing chamber means for combining the gases flowing through said first and second orifices and including coiled tubing for defining a convoluted path for at least one of the gases having a foil strip included therein for deflecting the flow of said at least one gas from an inner wall of said tubing toward a centerline of the path of said at least one gas thereby to disrupt gas flow such that said gas flow is not parallel to said inner wall.

A gas dilution system comprising:

• first and second gas storage means, said first gas storage means containing a pressurized standard gas mixture and said second gas storage means containing a pressurized dilution gas;
• first and second conduit means for conducting gas from said first and second gas storage means, respectively;
• pressure differential gauge means communicating with said first and second conduit means for comparing the pressure of gas in said first conduit means with the pressure of gas in said second conduit means;
• first and second orifices communicating with said first and second conduit means, respectively, each orifice being of a size for conducting pressurized gas therethrough at a constant velocity to provide respective gas flows in a proportion determined by the sizes of said orifices;
• and
• mixing chamber means for receiving and combining the gases conducted through said first and second orifices, said mixing chamber means comprising tubing means for defining a convoluted path for at least one of the gases.

A gas dilution system comprising:

• first and second gas storage means, said first gas storage means containing a pressurized standard gas mixture and said second gas storage means containing a pressurized dilution gas;
• first and second conduit means for conducting gas from said first and second gas storage means, respectively;
• pressure differential gauge means communicating with said first and second conduit means for comparing the pressure of gas in said first conduit means with the pressure of gas in said second conduit means;
• first and second orifices communicating with said first and second conduit means, respectively, for conducting pressurized gas therethrough at a constant velocity;
• and mixing chamber means for combining the gases conducted through said first and second orifices and including coiled tubing for defining a convoluted path for at least one of the gases having a foil strip included therein for deflecting the flow of said at least one gas from an inner wall of said tubing toward a centerline of the path of said at least one gas thereby to disrupt gas flow such that said gas flow is not parallel to said inner wall.