Optical gauge for determining the level of a medium in a container

• US 6,333,512 B1
• Filed: 07/09/1999
• Issued: 12/25/2001
• Est. Priority Date: 07/15/1998
• Status: Expired due to Fees

• Current Assignee: Alvin Wirthlin
• Original Assignee: Alvin Wirthlin
• Inventors: Wirthlin, Alvin R.
• Primary Examiner(s): Ham, Seungsook
• Assistant Examiner(s): HILL, BRADFORD K
• Application Number:
  US09/350,487
• Time in Patent Office: 900 Days
• Field of Search: 250/900, 250/901, 250/902, 250/903, 250/904, 250/905, 250/906, 250/907, 250/908, 250/573, 250/574, 250/577, 250/227.11, 250/361.R
• US Class Current: 250/577
• CPC Class Codes: G01F 23/2925 using electrical detecting means
• CPC Class Codes: G01F 23/686 using opto-electrically actuated indicating means
• CPC Class Codes: G01P 15/006 by making use of fluid seismic masses
• CPC Class Codes: Y10S 250/901 with gap between light guide elements, includes open light path preset

Abstract

An optical gauge for measuring the level of a liquid in a container comprises an elongate, tubular member with a central bore. A light source is positioned for projecting radiant energy into the bore along a length of the tubular member. An elongate light collector is spaced from the light source and extends along the length of the tubular member for receiving radiant energy from the light source. The light collector has opposite ends and is formed such that radiant energy incident on a length of the light collector is transmitted to the light collector ends. A light blocking member is located within the bore and extends between the light source and at least a portion of the elongate light collector for blocking at least a portion of the radiant energy from the light collector. The light blocking member is movable with respect to the light collector in response to change in liquid level within the tubular member for varying the position of the radiant energy incident on the light collector to thereby vary the amount of radiant energy transmitted to the light collector ends. At least one photosensor is positioned proximal at least one of the light collector ends for detecting the amount of radiant energy transmitted thereto. With this arrangement, the amount of radiant energy received by the light collector and detected by the at least one photosensor is indicative of the liquid level.

Claims

1. An optical gauge for measuring a level of a liquid in a container, the optical gauge comprising:

an elongate, tubular member having opposite ends and a bore extending between the opposite ends, the bore being adapted to receive liquid that may be present in the container;

a light source positioned for projecting radiant energy into the bore from one end of the tubular member;

a continuous elongate light collector extending along a length of the tubular member for receiving, at least indirectly, radiant energy from the light source, the light collector having opposite ends and being formed such that radiant energy incident on a length of the light collector is transmitted to the light collector ends;

a light blocking member located within the bore and operably associated with an upper surface of the liquid for blocking at least a portion of the radiant energy from the light collector between the light blocking member and the other end of the tubular member, the light blocking member being movable with respect to the light collector in response to change in liquid level within the tubular member for varying the position of the radiant energy incident on the light collector to thereby vary the amount of radiant energy transmitted to the light collector ends; and

at least one photosensor positioned for detecting the amount of radiant energy transmitted to at least one of the light collector ends,

wherein the amount of radiant energy transmitted to the at least one light collector end and detected by the at least one photosensor is indicative of the liquid level.

2. An optical gauge according to claim 1, wherein the light blocking member comprises at least one float that is adapted to ride on an upper surface of the liquid that may be present in the tubular member such that measurement of the liquid level is independent of the degree of transparency of the liquid.

3. An optical gauge according to claim 2, wherein the float is opaque to the radiant energy.

4. An optical gauge according to claim 2, wherein the float is spherical in configuration.

5. An optical gauge according to claim 4, wherein the light source is positioned at the one end of the tubular member coincident with a central axis of the bore.

6. An optical gauge according to claim 5, wherein the float has a reflective surface for reflecting the radiant energy toward the light collector between the float and the one end.

7. An optical gauge according to claim 6, wherein the light source is collimated.

8. An optical gauge according to claim 1, wherein the light blocking member comprises a plurality of floats that are adapted to ride on an upper surface of the liquid that may be present in the tubular member.

9. An optical gauge according to claim 1, wherein the light blocking member comprises an upper surface of the liquid in the tubular member.

10. An optical gauge according to claim 1, wherein the bore comprises at least one elongate channel, the light collector being associated with the at least one channel.

11. An optical gauge according to claim 10 wherein the bore includes a reflective surface.

12. An optical gauge according to claim 1, wherein the light source is arranged to project radiant energy into the bore from the one end of the tubular member at an acute angle with respect to a central axis of the bore such that the radiant energy is incident on an inner surface of the bore and the light collector between the light blocking member and the one end of the tubular member.

13. An optical gauge according to claim 1, wherein the light blocking member comprises the liquid in the tubular member.

14. An optical gauge according to claim 1, and further comprising means for damping the transfer of fluid between the bore and the container.

15. An optical gauge according to claim 1 wherein the light collector comprises a fluorescent-doped fiber optic.

17. An optical gauge according to claim 10, wherein the light collector comprises a fluorescent-doped fiber optic.

16. An optical gauge for measuring a level of transparent or translucent liquid, the optical gauge comprising:

an elongate, tubular member having opposite ends with a bore extending between the opposite ends, the bore having a central axis and being adapted to receive liquid;

a light source positioned for projecting radiant energy into the bore along the central axis from one of the ends of the tubular member;

an elongate continuous light collector spaced from the light source and extending along a length of the tubular member for receiving, at least indirectly, radiant energy from the light source, the light collector having opposite end and being formed such that radiant energy incident on the light collector is transmitted to the light collector ends;

a float positioned in the bore for movement with an upper surface of the liquid, the float being opaque to the radiant energy for blocking the radiant energy from a) the liquid, and b) the light collector between the float and the other end of the tubular member, wherein movement of the float with respect to the light collector varies the position of the radiant energy incident on the light collector to thereby vary the amount of radiant energy transmitted to the light collector ends; and

at least one photosensor positioned for detecting the amount of radiant energy transmitted to at least one of the light collector ends;

wherein the amount of radiant energy transmitted to the at least one light collector end and detected by the at least one photosensor is indicative of the liquid level independent of the degree of transparency of the liquid.

18. An optical gauge according to claim 16, wherein the float has a reflective surface for reflecting the radiant energy toward the light collector between the float and the one end.

19. An optical gauge according to claim 16, wherein the light source is arranged to project radiant energy into the bore from the one end of the tubule member at an acute angle with respect to a central axis of the bore such that the radiant energy is incident on an inner surface of the bore and the light collector between the light blocking member and the one end of the tubular member.

20. An optical gauge according to claim 16, wherein the bore comprises at least one elongate channel, the light collector being associated with the at least one channel.