ENHANCED ENCLOSURES FOR ACOUSTICAL GAS CONCENTRATION SENSING AND FLOW CONTROL

摘要

Mass-transfer rate control arrangement and method in which a process precursor mixture is produced containing carrier gas and a process precursor gas. A quantity of the process precursor present in the process precursor mixture is acoustically sensed to produce a sensor output. A dilution gas is provided and the process precursor mixture and the dilution gas are separately conveyed to a diution point, at which a diluted mixture of the dilution gas and the process precursor mixture is achieved. A relative flow rate of the carrier gas and the dilution gas is automatically controlled in response to the sensor output such that the diluted mixture at the dilution point has a prescribed mass transfer rate of the precursor gas.

主权项

1. An apparatus for acoustically determining a property of a test medium, comprising:
an enclosure including a base and a cover, said base and said cover cooperating to define a chamber; an acoustical sensor mounted to said base, said acoustical sensor including a first acoustical transducer defining a first exposed face and a second acoustical transducer defining a second exposed face, said first exposed face and said second exposed face being substantially parallel and adapted for contact with said test medium and defining a gap therebetween; at least one heating element operatively coupled with said enclosure, wherein a first portion of said enclosure is operatively coupled with said at least one heating element, said first portion being vertically oriented, wherein a second portion of said enclosure is not operatively coupled with said at least one heating element, said second portion being vertically oriented and opposing said first portion of said enclosure.