Flow controller-flow sensor assembly for gas chromatographs and the like

Patent 4096746 Issued on June 27, 1978. Estimated Expiration Date:

June 27, 1995. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.

Abstract Claims Description Full Text

Patent References

1640842

1699676

2182873

2711187

2862162

3078713

3792609

Inventors

Assignee

The Perkin-Elmer Corporation

Application

No. 05/772179 filed on 02/25/1977

US Classes:

73/861.52, With restriction137/501, Pressures across fixed choke73/1.25, Orifice or restriction73/1.34With signal processing, span or set point adjustment (e.g., zero correction)

Examiners

Primary: Queisser, Richard C.
Assistant: Kreitman, Stephen A.

Attorney, Agent or Firm

International Classes

G05D 7/00 (20060101)
G05D 7/01 (20060101)
G01F 1/40 (20060101)
G01F 1/34 (20060101)
G01N 30/02 (20060101)
G01N 30/00 (20060101)
G01N 30/32 (20060101)

Abstract

There is disclosed a flow controller-flow sensor combination especiably suited for gas chromatograph applications wherein a transducer monitors the pressure at the inlet and outlet of a flow restrictor element in the controller thereby to monitor the differential pressure across the restrictor; the differential pressure being proportional to the gas velocity through the flow restrictor element. In one form of the invention, a second flow restrictor element is provided in one input line to the transducer which preferably is of relatively low impedance in order to delay the buildup of the pressure head of the corresponding input of the transducer sensor, thus to enable the pressure at the outlet of the flow restrictor in the controller to buildup gradually so as not to exceed the maximum differential pressure specifications for said transducer.