Molar gas-flow controller
AssigneeThe Perkin-Elmer Corporation
InventorsRichard L. Bersin, William H. Clouser
Life of this patent
Estimating the term…
Abstract
An apparatus for controlling the volume of flow of a gas. A reference volume has an input conduit connected to the source of gas and an output conduit connected to a utilization device. Valves in the input and output conduits are cyclically controlled to permit pressure in the reference volume to reach a high and then to attain a low. The reference volume pressure is measured twice during each cycle to provide voltages representative of the high and low pressures. Circuit means control the time and duration of operation of the valves to cause the difference between the high and low pressures to equal a predetermined value.
Claims9
An apparatus for controlling gas flow, comprising in combination,
- a reference volume having an input conduit and an output conduit,
- a source of gas connected to said input conduit,
- first and second normally closed valves disposed in said input and output conduits, respectively,
- control means for opening and closing said first and second valves to cause the difference between high and low pressures in said reference volume to equal a predetermined value,
- said control means comprising,
- transducer means connected to said reference volume and a reference pressure providing an output voltage representative of the pressure in said reference volume,
- generator means cyclically providing first, second, third and fourth pulses,
- first means responsive to said first pulse for opening said first valve for the duration of said first pulse, once each cycle,
- second means responsive to said third pulse for opening said second valve for the duration of said third pulse once each cycle,
- third means for closing said second valve when said output voltage equals a predetermined value.
Dependencies are inferred from the claim text.