Radiation detector probe for ionising radiation

Patent metadata

Field	Value
Publication number	US-9625591-B2
Application number	US-201214238551-A
Country	US
Kind code	B2
Filing date	Aug 16, 2012
Priority date	Aug 17, 2011
Publication date	Apr 18, 2017
Grant date	Apr 18, 2017

Abstract

A detector probe for detecting ionizing radiation includes at least one detector ( 14 ) mounted on a support ( 12 ), and an electrically operated source of heat ( 18 ) arranged on the support in proximity to the detector so that the temperature of the detector may be changed by operation of the heat source. The detector probe may be used in the manufacture of a level gauge or density profiler.

First claim

The invention claimed is:

1. A level gauge or density profiler comprising at least one source of ionising radiation and a detector probe for detecting the ionising radiation, the detector probe comprising:
at least 10 radiation detectors adapted for detecting ionising radiation comprising alpha particles, beta particles, gamma radiation and/or neutrons, the radiation detectors being supported along an elongate support, wherein
an electrically operated self-regulating distributed heat source is arranged along the elongate support in proximity to the detectors so that the temperature of the detectors may be changed by operation of the distributed heat source, the heat source being an electrical device incorporating a conducting material having a resistance which is variable according to a temperature of the heat source, and
the radiation detectors, support and distributed heat source are enclosed within a dip pipe and there is thermal insulation between an inner wall of the dip pipe and the detectors.

2. The level gauge or density profiler according to claim 1 , wherein said detectors are selected from the group consisting of Geiger-Müller tubes and scintillation detectors.

3. The level gauge or density profiler according to claim 1 , wherein each detector is mounted on a printed circuit board for carrying the control and data signals to and from the detector.

4. The level gauge or density profiler according to claim 3 , wherein said support comprises a reinforcing structure for reinforcing the circuit board to provide strength and stiffness over the length of the probe.

5. The level gauge or density profiler according to claim 1 , wherein the distributed heat source distributes heat through a greater part of the probe.

6. The level gauge or density profiler according to claim 1 , wherein the distributed heat source comprises a trace heat source.

7. The level gauge or density profiler according to claim 1 , further comprising a temperature sensor.

8. The level gauge or density profiler according to claim 1 , wherein the distributed heat source is operable to maintain the detectors within a temperature range of 150 to −55° C.

9. The level gauge or density profiler according to claim 1 , which is intrinsically safe, as defined by European Standard EN 60079:2009.

10. A density profiler according to claim 1 for measuring a level of two or more material phases within a container, the density profiler comprising a linear array of sources of ionising radiation, at least one said detector probe for detecting ionising radiation comprising a linear array of radiation detectors, a power source and a signal and a data processor adapted for calculating a density profile of the material phases using signals generated by the detectors in response to radiation received from the sources; said source array and detector probe(s) being arranged so that ionising radiation from each source passes along a straight line through a portion of the container to a detector carried on the detector probe.

11. The level gauge or density profiler according to claim 1 , wherein the distributed heat source comprises a heating cable.

12. The level gauge or density profiler according to claim 1 , wherein the detector probe is configured to be maintained in a temperature range of 110° C. to −55° C.

13. The level gauge or density profiler according to claim 1 , wherein the detector probe is surrounded by a protective layer comprising a plastic tube.

14. The level gauge or density profiler according to claim 1 , wherein the detector probe is housed in a titanium housing.

15. The level gauge or density profiler according to claim 1 , wherein the titanium housing has a thickness that renders the titanium housing substantially transparent to gamma radiation.

16. The level gauge or density profiler according to claim 1 , wherein the thermal insulation has a thermal conductivity <0.05 W/m/K.

17. The level gauge or density profiler according to claim 1 , wherein the heat source is a self-regulating heating cable.

Assignees

• Field Robert Shaun
• Howe Geoffrey Stuart
• Lambert Simon
• Johnson Matthey Plc

Inventors

• Field Robert Shaun
• Howe Geoffrey Stuart
• Lambert Simon

Classifications

• G01F23/288

  X-rays; Gamma rays {or other forms of ionising radiation} · CPC title

• G01F23/2885 Primary

  for discrete levels · CPC title

• G01N9/24

  by observing the transmission of wave or particle radiation through the material · CPC title

• G01T3/06

  with scintillation detectors · CPC title

• G01T1/20

  with scintillation detectors · CPC title