Radiation monitor

• US 8,330,106 B2
• Filed: 09/08/2006
• Issued: 12/11/2012
• Est. Priority Date: 09/09/2005
• Status: Active Grant

• Current Assignee: Tracerco Ltd.
• Original Assignee: Johnson Matthey PLC
• Inventors: Green, Darrell, Cunningham, Colin
• Primary Examiner(s): Porta, David
• Assistant Examiner(s): Igyarto, Carolyn
• Application Number:
  US12/065,852
• Publication Number:
  US 20090114833A1
• Time in Patent Office: 2,286 Days
• Field of Search: 250/336.1, 313/93, D10/47
• US Class Current: 250/336.1
• CPC Class Codes: G01T 1/167 Measuring radioactive content of objects, e.g. contamination whole body counters G01T1/163
• CPC Class Codes: G01T 1/18 with counting-tube arrangements, e.g. with Geiger counters tubes H01J47/08; with alarm provision G01T7/125

Abstract

The invention comprises a radiation and contamination monitor for the monitoring of radiation and contamination. The instrument is intrinsically safe and comprises a radiation detector, a power source, a signal processor and a display, said power source, signal processor and display being housed within a sealed instrument housing formed from a non-metallic material which is resistant to static discharge. The detector may be housed in a detachable housing for contamination monitoring.

Claims

1. An electronic instrument for the measurement of radiation comprising:

a radiation detector comprising a Geiger Mü

ller tube which is adapted for the detection of low energy β

- or α

- particles,

a power source,

a signal processor and a display,

wherein said power source, said signal processor and said display are housed within a sealed instrument housing formed from a non-metallic material which is resistant to static discharge and wherein the power, processor and display circuits are not sparkable, such that the instrument is intrinsically safe, and further wherein the instrument is a radioactive contamination monitor.

2. The instrument according to claim 1, wherein said instrument housing comprises an integral handle portion.

3. The instrument according to claim 1, wherein said Geiger Mü

ller tube is energy-compensated and is suitable for the detection of gamma and X-radiation having energies in the range from 40 keV to 1.4 MeV.

4. The instrument according to claim 1 further comprising a separate detector housing and wherein the radiation detector is housed within said separate detector housing, said separate detector housing having a window through which radiation may pass to the detector and having communication means by which signals generated by the detector may be transmitted to said signal processor within the instrument housing.

5. The instrument according to claim 4, wherein said communication means comprises a cable.

6. The instrument according to claim 4, wherein said communication means comprises wireless transmission and receiving means.

7. The instrument according to claim 4, wherein the detector housing is mountable on and demountable from the instrument housing.

8. The instrument according to claim 1, wherein said display comprises at least one analogue display and at least one alphanumeric digital display.

9. The instrument according to claim 1, wherein the instrument is calibrated to display the radiation density for more than one common nuclide.

10. The instrument according to claim 9, calibrated to calculate radiation for at least two isotopes selected from the group consisting of ²⁴¹Am, ¹⁴C, ²¹⁰Pb (dry), ²¹⁰Pb (wet), ²²⁶Ra (dry), ²²⁶Ra (wet), ⁹⁰Sr and ³⁶Cl.

11. The instrument according to claim 9 further comprising a non-transitory computer readable medium including a computer program configured to convert between a calibration for a first one of said common nuclides and a calibration for a second one of said common nuclides.

12. The instrument according to claim 9 further comprising a memory function which stores a date of calibration.

13. The instrument according to claim 9, comprising means for selecting the desired calibration.

14. The instrument according to claim 1, wherein the housing is sealed to prevent the ingress of gas or liquid.