摘要 |
A method and system are described for controlling the delivery of vapor from a bubbler containing a supply of liquid through which a carrier gas is bubbled and from which bubbler vapors are delivered in a vapor stream entrained with the carrier gas. In general, embodiments of the invention involve utilizing the pressure of the vapor leaving the bubbler as the specific characteristic monitored and controlled to ensure that the concentration level of carrier gas to vapor is maintained at the desired level throughout the manufacturing process. Embodiments of the invention involve introducing a concentration detector within the flow path of the bubbler vapors from the bubbler and having the output of the concentration detector input to a concentration controller. The concentration controller compares the concentration value received from the concentration detector to a desired concentration value determined for the system. In order to correct for any discrepancies between the measured and desired concentration levels, the concentration controller activates the opening and/or closing of a valve, which as the concentration detector is positioned within the flow of bubbler vapor exiting the bubbler. |