Pressure-sensitive optrode

• US 4,509,370 A
• Filed: 09/30/1982
• Issued: 04/09/1985
• Est. Priority Date: 09/30/1982
• Status: Expired due to Term

• Current Assignee: Regents of the University of California (University of California)
• Original Assignee: Regents of the University of California (University of California)
• Inventors: Hirschfeld, Tomas B.
• Primary Examiner(s): WOODIEL, DONALD
• Application Number:
  US06/430,578
• Time in Patent Office: 922 Days
• Field of Search: 73/705, 73/DIG. 11, 73/301, 73/745, 73/188, 73/729, 73/863.23, 250/227, 250/231 P, 372/40, 372/41, 128/673, 128/634, 374/159
• US Class Current: 73/705
• CPC Class Codes: G01D 5/268 using optical fibres G01D5/28 - G01D5/38 take precedence
• CPC Class Codes: G01K 1/024 for remote indication
• CPC Class Codes: G01L 9/0039 using photoelectric means
• CPC Class Codes: G01L 9/0076 using photoelectric means
• CPC Class Codes: G01L 9/0077 for measuring reflected light
• CPC Class Codes: G01L 9/0089 Transmitting or indicating the displacement of pistons by electrical, electromechanical, magnetic or electromagnetic means G01L9/0008 takes precedence

Abstract

Apparatus and method for sensing changes in pressure and for generating optical signals related to changes in pressure. Light from a fiber optic is directed to a movable surface which is coated with a light-responsive material, and which moves relative to the end of the fiber optic in response to changes in pressure. The same fiber optic collects a portion of the reflected or emitted light from the movable surface. Changes in pressure are determined by measuring changes in the amount of light collected.

Claims

1. An apparatus for sensing changes in pressure and for generating optical signals related to said changes in pressure, the apparatus comprising:

(a) a fiber optic through which light from at least one associated light source is transmitted from a first end of the fiber optic to a second end of the fiber optic;

(b) resilient means operationally associated with the second end of the fiber optic, the resilient means having a movable surface which moves relative to the second end of the fiber optic along an axis of the fiber optic in response to changes in pressure and the movable surface having a fluorescent composition attached to one side such that light transmitted by the fiber optic impinges on the fluorescent composition, causing it to generate an optical signal;

(c) a beam splitting means adjacent to the first end of the fiber optic for separating light from at least one associated light source from the optical signal generated by the fluorescent composition and transmitted by the fiber optic; and

(d) detection means adjacent to the beam-splitting means for collecting and analyzing the optical signal generated by the fluorescent composition and transmitted by the fiber optic.

2. An apparatus as recited in claim 1, the apparatus further comprising at least one light source, wherein a substantial portion of the radiative power generated by the at least one light source occurs at wavelengths within the range of preferential wavelengths for exciting the fluorescent molecules of the fluorescent composition.

3. An apparatus as recited in claim 2, wherein said fluorescent composition is fluorescein.

4. An apparatus as recited in claim 2, wherein said fluorescent composition is a solid material capable of lasing.

5. An apparatus as recited in claim 4, wherein said solid material is a rare earth- or transition metal-doped glass.

6. An apparatus as recited in claim 5, wherein said rare earth- or transition metal-doped glass is uranyl-doped glass.

7. An apparatus as recited in claim 4, wherein said solid material is a crystal.

8. An apparatus as recited in claim 7, wherein said crystal is ruby.

9. An apparatus as recited in claim 1, wherein said resilient means is a piston, and wherein said movable surface is one side of the piston.

10. An apparatus as recited in claim 1, wherein said resilient means is a diaphragm, and wherein said movable surface is one side of the diaphragm.

11. An apparatus as recited in claim 1, wherein aid resilient means is an elastic membrane, and wherein said movable surface is one side of the elastic membrane.

12. An apparatus as recited in claim 11, wherein said elastic membrane is made of plastic.

13. An apparatus as recited in claim 12, wherein said plastic is collodion.

14. An apparatus as recited in claim 1, wherein said resilient means is a bellows, and wherein said movable surface is a first end of the bellows, and said second end of said fiber optic is adjacent to a second end of the bellows.

15. An apparatus as recited in claim 14, wherein said bellows is made of a material selected from the group consisting of stainless steel, zirconium, and electroformed nickel.