Remote sensor head for laser level measurement devices

• US 6,040,897 A
• Filed: 04/29/1998
• Issued: 03/21/2000
• Est. Priority Date: 04/29/1998
• Status: Expired due to Term

• Current Assignee: Kama-Tech (HK) Limited
• Original Assignee: Laser Technology Incorporated (Laser Technology)
• Inventors: Clifford, Bruce, Harrison, John
• Primary Examiner(s): Buczinski, Stephen C.
• Application Number:
  US09/069,447
• Time in Patent Office: 692 Days
• Field of Search: 356/4.01, 356/3.01, 356/5.01, 356/5.1, 73/293, 73/290 R
• US Class Current: 356/4.01
• CPC Class Codes: G01F 23/2928 using light reflected on the material surface
• CPC Class Codes: G11B 5/5504 across tape tracks

Abstract

Disclosed is an optical sensor used for remote laser level monitoring in liquid storage vessels. The sensor is mounted directly to a standard tank nipple, located on top of the vessel, by a threaded connecting means and is linked to a laser measurement device via fiber optic cabling. The level in the vessel is measured as a function of the time required for a laser signal to be transmitted from the sensor, reflected off the liquid surface and returned to the receiver lens located in the sensor.

Claims

1. A remote sensor head for laser level measurement in liquid storage vessels, said sensor head comprising:

a sleeve, said sleeve generally cylindrical in shape, with a component end opposite a connecting end, said sleeve being hollow throughout providing fluid connectivity between said component end and said connecting end and forming a sleeve interior cavity;

a base, said base generally cylindrical in shape with a cable end opposite a component end, said base being hollow on said component end and forming a base interior cavity, said base connected to said sleeve at said component end by a plurality of leveling screws such that the longitudinal axis of said base is parallel to the longitudinal axis of said sleeve and such that said base interior cavity is in fluid communication with said sleeve interior cavity;

a transmitter lens assembly, said transmitter lens assembly having a generally cylindrical shape, said transmitter lens assembly being hollow throughout with a transmitter lens assembly cable end in fluid communication with a transmitter lens assembly component end, said transmitter lens assembly secured to said base interior cavity in a manner such that the longitudinal axis of said transmitter lens assembly is parallel to the longitudinal axis of said sleeve and said base and such that said transmitter lens assembly component end is in fluid communication with said sleeve interior cavity and said base interior cavity;

a receiver lens assembly, said receiver lens assembly being generally cylindrical in shape and hollow throughout with a receiver lens assembly cable end in fluid communication with a receiver lens assembly component end, said receiver lens assembly secured to said base interior cavity in a manner such that the longitudinal axis of said receiver lens assembly is parallel to the longitudinal axis of said sleeve and said base and such that said receiver lens assembly component end is in fluid communication with said sleeve interior cavity and said base interior cavity;

a window, said window affixed perpendicular to the longitudinal axis of said sleeve interior cavity and spanning the interior cross-section of said sleeve and secured by a window retaining ring;

a transmitter lens, said transmitter lens affixed in said transmitter lens assembly perpendicular to the longitudinal axis of said transmitter lens assembly and secured by a transmitter lens retaining ring; and

a receiver lens, said receiver lens affixed in said receiver lens assembly perpendicular to the longitudinal axis of said receiver lens assembly and secured by a receiver lens retaining ring.

2. The sensor head of claim 1, wherein said base further comprises:

a transmitting lens aperture, said transmitting lens aperture generally cylindrical in shape with a threaded connecting means along the interior surface thereof and providing fluid connectivity between said base interior cavity and said base cable end; and

a receiving lens aperture, said receiving lens aperture generally cylindrical in shape with a threaded connecting means along the interior surface thereof and providing fluid connectivity between said base interior cavity and said base cable end.

3. The sensor head of claim 2, wherein said sensor head further comprises:

a transmitter receptacle base, said transmitter receptacle base generally cylindrical in shape and hollow throughout with a transmitter receptacle base cable end in fluid communication with a transmitter receptacle base component end, said transmitter receptacle base secured to said base cable end in a manner such that the longitudinal axis of said transmitter receptacle base is parallel to the longitudinal axis of said base and such that said transmitter receptacle base component end is in fluid communication with said transmitter lens aperture;

a receiver receptacle base, said receiver receptacle base generally cylindrical in shape and hollow throughout with a receiver receptacle base cable end in fluid communication with a receiver receptacle base component end, said receiver receptacle base secured to said base cable end in a manner such that the longitudinal axis of said receiver receptacle base is parallel to the longitudinal axis of said base and such that said receiver receptacle base component end is in fluid communication with said receiver lens aperture;

a transmitter fiberoptic terminating connector, said transmitter fiberoptic terminating connector affixed to said transmitter receptacle base cable end, facilitating connection of said transmitter fiberoptic terminating connector to the transmitter fiberoptic cable of a laser measurement device such that an optical laser measurement signal can be transmitted by said laser measurement device through said transmitter lens; and

a receiver fiberoptic terminating connector, said receiver fiberoptic terminating connector affixed to said receiver receptacle base cable end, facilitating connection of said receiver fiberoptic terminating connector to the receiver fiberoptic cable of said laser measurement device such that an optical laser measurement signal can be received by said laser measurement device through said receiver lens.

4. The sensor head of claim 3, wherein said transmitter lens assembly further comprises a transmitter lens assembly threaded connecting means on the exterior surface thereof, said transmitter lens assembly threaded connecting means securing said transmitter lens assembly to said base interior cavity in a manner such that the distance between said transmitter lens and said laser measurement device transmitter fiberoptic cable can be adjusted by rotating said transmitter lens assembly and locked in place using a transmitter lens assembly locking screw.

5. The sensor head of claim 3, wherein said receiver lens assembly further comprises a receiver lens assembly threaded connecting means on the exterior surface thereof, said receiver lens assembly threaded connecting means securing said receiver lens assembly to said base interior cavity in a manner such that the distance between said receiver lens and said laser measurement device receiver fiberoptic cable can be adjusted by rotating said receiver lens assembly and locked into place using a receiver lens assembly locking screw.

6. The sensor head of claim 3, wherein said sleeve further comprises a sleeve threaded connecting means the exterior surface of said sleeve component end that facilitates connection to a standard NPT nipple-type connector.

7. The sensor head of claim 3, wherein said sleeve further comprises a sleeve flanged connecting means the exterior surface of said sleeve component end that facilitates connection to a standard flange connector.

8. The sensor head of claim 3, wherein a waterproof seal is created between said base and said sleeve, between said window and said sleeve interior cavity, between said transmitter fiberoptic terminating connector and said transmitter receptacle base cable end, and between said receiver fiberoptic terminating connector and said receiver receptacle base cable end, said waterproof seal created by a device selected from the group comprising O-rings, gaskets and washers.

9. The sensor head of claim 3, wherein said sensor head facilitates the use or remotely located laser measurement devices to calculate the level of a liquid in a liquid storage vessel, connecting said sensor head to the top surface of said liquid storage vessel in a manner such that the sleeve interior cavity is in fluid connectivity with the interior cavity of said liquid storage vessel and oriented such that the longitudinal axis of said sensor head is perpendicular to the surface of the liquid contained within said liquid storage vessel.