RADIATION MONITOR

• US 20090114833A1
• Filed: 09/08/2006
• Published: 05/07/2009
• Est. Priority Date: 09/09/2005
• Status: Active Grant

• Current Assignee: Tracerco Ltd.
• Original Assignee: Johnson Matthey PLC
• Inventors: Cunningham, Colin, Green, Darrell
• Granted Patent: US 8,330,106 B2
• Time in Patent Office: Days
• US Class Current: 250/388
• 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 instrument for the measurement of radiation comprising a radiation detector, 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 such that the instrument is intrinsically safe.

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

3. An instrument according to claim 1, wherein said radiation detector comprises a Geiger Muller tube.

4. An instrument according to claim 3 wherein said Geiger Muller 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.

5. An instrument according to claim 3 wherein said Geiger Muller tube is adapted for the detection of low energy β

- or α

- particles.

6. An instrument according to claim 5 which is adapted for use as a radioactive contamination monitor.

7. An instrument according to claim 1, wherein the radiation detector is housed within a 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 a signal processor within the instrument housing.

8. An instrument according to claim 7, wherein said communication means comprises a cable.

9. An instrument according to claim 7, wherein said communication means comprises wireless transmission and receiving means.

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

11. An instrument according to claim 1, further comprising at least one analogue and at least one alphanumeric digital display.

12. An instrument according to claim 1, which is adapted for use as a radiation dose rate monitor.

13. An instrument according to claim 12, calibrated to display a direct reading of dose rate.

14. An instrument according to claim 12, adapted to display a cumulative dose over a selected period of time.

15. An instrument according to claim 1, calibrated to display the radiation density for more than one common nuclide and wherein the appropriate calibration may be selected by the user.

16. An instrument according to claim 15, 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.

17. An instrument according to claim 15, further comprising software programmed to convert between the calibration scales.

18. An instrument according to claim 1, further comprising a memory function adapted to store date of calibration.

21. An instrument according to claim 1, wherein the power, processor and display circuits are not sparkable, the power supply is potted and the housing is sealed to prevent the ingress of gas or liquid.

22. An instrument according to claim 1, which is suitable for use in hazardous areas, zones 0, 1 and 2.

19. (canceled)

20. (canceled)