Sectioned probe for a radar level gauge

Patent metadata

Field	Value
Publication number	US-9383246-B2
Application number	US-201314019854-A
Country	US
Kind code	B2
Filing date	Sep 6, 2013
Priority date	Sep 6, 2013
Publication date	Jul 5, 2016
Grant date	Jul 5, 2016

Abstract

The present invention relates to a guided wave radar level gauge comprising a transceiver, processing circuitry and a single conductor probe comprising at least two elongate probe sections. A connector extending from a first end of the probe section comprises: an abutment portion having a diameter smaller than a diameter of the probe section, an intermediate portion, having a diameter smaller than the abutment portion, arranged between the probe section and the abutment portion and an outside threaded portion. A second end portion of the probe section comprises a sleeve comprising an inside threaded receiving portion receiving the connector; a passage through a sidewall of the sleeve being located off-center in relation to a longitudinal central axis of the probe section. The probe further comprises a locking pin to be arranged in the passage locking two assembled probe sections by limiting movement of the abutment portion in a longitudinal direction.

First claim

What is claimed is:

1. A guided wave radar level gauge for determining a filling level of a product contained in a tank, which level gauge comprises:
a transceiver for transmitting electromagnetic transmission signals and receiving reflected electromagnetic signals reflected at a surface of said product;
processing circuitry connected to said transceiver and configured to determine said filling level based on said received reflected electromagnetic signals;
a single conductor probe configured to guide said electromagnetic transmission signals towards said surface and to guide said reflected electromagnetic signals back to said transceiver, said probe comprising at least two elongate probe sections, each probe section being electrically conductive and having a circular cross section;
wherein a connector permanently attached to and extending from a first end portion of each probe section comprises:
an abutment portion having a diameter smaller than a diameter of said probe section;
an intermediate portion, arranged between said probe section and said abutment portion, said intermediate portion having a diameter smaller than said abutment portion; and

an outside threaded portion;
wherein a second end portion of said probe section comprises:
a sleeve permanently attached to said probe section and comprising a receiving portion being inside threaded and configured to receive said outside threaded portion of said connector;
a passage through a sidewall of said sleeve, said passage being located off-center in relation to a longitudinal central axis of said probe section, such that said passage is located radially outside of said intermediate portion and radially inside of said abutment portion when a connector of a first probe section is fitted in a sleeve of a second probe section; and

wherein said probe further comprises a locking pin configured to be arranged in said passage such that said first probe section is locked to said second probe section by limiting movement of said abutment portion in a longitudinal direction;
wherein each probe section has a diameter not greater than 20 mm,
wherein the first end portion of the first probe section abuts the sleeve of the second probe section when the probe is assembled, and
wherein the single conductor probe is straight.

2. The level gauge according to claim 1 , wherein said outside threaded portion is arranged between said intermediate portion and said probe section.

3. The level gauge according to claim 1 , wherein said passage extends through two sidewalls of said sleeve.

4. The level gauge according to claim 3 , wherein said locking pin is a split pin.

5. The level gauge according to claim 1 , wherein said locking pin is tapered to engage with said sleeve when inserted into said passage.

6. The level gauge according to claim 1 , wherein said passage through said sidewall is inside threaded, and said locking pin is outside treaded and configured to be screwed into said passage.

7. The level gauge according to claim 1 , wherein said abutment portion comprises outside threads configured to be threaded into inside threads of said receiving portion.

8. The level gauge according to claim 1 , wherein said probe section is substantially solid.

9. The level gauge according to claim 1 , wherein said connector and said probe section are made in one piece from a metallic cylinder.

10. The level gauge according to claim 1 , wherein said sleeve and said probe section are made in one piece from a metallic cylinder.

11. The level gauge according to claim 1 , wherein said probe section is substantially tubular.

12. The level gauge according to claim 1 , further comprising a transceiver connector for connecting said probe to said transceiver.

13. The level gauge according to claim 1 , wherein said probe section further comprises a tool engagement portion arranged adjacent to at least one of said first end portion and said second end portion of said probe section.

14. Method for arranging a guided wave radar level gauge in a tank, which level gauge system comprises:
a transceiver for transmitting electromagnetic transmission signals and receiving reflected electromagnetic signals reflected at a surface of said product;
processing circuitry connected to said transceiver and configured to determine said filling level based on said received reflected electromagnetic signals;
a single conductor probe configured to guide said electromagnetic transmission signals towards said surface and to guide said reflected electromagnetic signals back to said transceiver, said probe comprising at least two elongate probe sections, each probe section being electrically conductive and having a circular cross section;
wherein a connector permanently attached to and extending from a first end portion of each probe section comprises:
an abutment portion having a diameter smaller than a diameter of said probe section;
an intermediate portion, arranged between said probe section and said abutment portion, said intermediate portion having a diameter smaller than said abutment portion; and

an outside threaded portion;
wherein a second end portion of said probe section comprises:
a sleeve permanently attached to said probe section and comprising a receiving portion being inside threaded and configured to receive said outside threaded portion of said connector; and
a passage through a sidewall of said sleeve, said passage being located off-center in relation to a longitudinal central axis of said probe section, such that said passage is located radially outside of said intermediate portion and radially inside of said abutment portion when a connector of a first probe section is fitted in a sleeve of a second probe section;

said method comprising;
assembling said probe by screwing a connector of a first probe section into a sleeve of a second probe section such that the first end portion of the first probe section abuts the sleeve of the second probe section, wherein the assembled probe is straight;
inserting a locking pin into said passage of said sleeve such that said locking pin prevents said abutment portion from moving in a longitudinal direction of said probe, thereby preventing said first and second probe sections from being disassembled;
securing said locking pin to said sleeve;
arranging said straight probe vertically in the tank;
mechanically connecting said tank feedthrough connector of said first probe section to a tank feedthrough such that said probe extends into said tank;
arranging said transceiver and said processing circuitry in connection with said tank feedthrough; and
electrically connecting said transceiver to said probe.

15. The method according to claim 14 wherein inserting said locking pin comprises inserting a split pin into said passage and through said sleeve, and bending at least one tine of said split pin such that said split pin is prevented from leaving said passage.

16. The method according to claim 14 , wherein inserting said locking pin comprises screwing said locking pin into said passage of said sleeve.

Assignees

• Rosemount Tank Radar Ab

Inventors

• Hagglund Bengt

Classifications

• H01Q1/50

  Structural association of antennas with earthing switches, lead-in devices or lightning protectors · CPC title

• H01Q1/225

  used in level-measurement devices, e.g. for level gauge measurement · CPC title

• H01P1/225

  Coaxial attenuators (H01P1/23 takes precedence) · CPC title

• G01F23/284 Primary

  Electromagnetic waves · CPC title

• F16L15/08

  with supplementary elements (F16L15/04 takes precedence) · CPC title