Intelligent radiation monitor

• US 4,642,463 A
• Filed: 01/11/1985
• Issued: 02/10/1987
• Est. Priority Date: 01/11/1985
• Status: Expired due to Fees

• Current Assignee: William H. Thoms
• Original Assignee: William H. Thoms
• Inventors: Thoms, William H.
• Primary Examiner(s): Howell, Janice A.
• Assistant Examiner(s): Hannaher, Constantine
• Application Number:
  US06/690,547
• Time in Patent Office: 760 Days
• Field of Search: 250/388, 250/370 J, 250/370 F, 250/336.1, 364/527, 364/414
• US Class Current: 250/336.1
• CPC Class Codes: G01T 1/026 Semiconductor dose-rate meters
• CPC Class Codes: G01T 1/17 Circuit arrangements not adapted to a particular type of detector pulse-selection circuits H03K, G01R
• CPC Class Codes: G01T 7/12 Provision for actuation of an alarm

Abstract

An intelligent radiation monitor is disclosed which includes, as major components, a radiation detector (for detecting real time radiation rate), a digital processor and a display. The digital processor includes intelligence to perform several useful, and novel, functions. The digital processor is responsive to externally input information corresponding to alarm radiation rate, alarm radiation dose and alarm time-to-go. The digital processor integrates the perceived real time radiation rate to produce total dose information. The processor can then compare total dose information to alarm dose, compare sensed radiation rates to alarm rate and compute time-to-go, by dividing the difference between alarm dose and total dose by the present radiation rate, and finally comparing computed time-to-go to alarm time to go. The processor initiates an alarm condition for altering the user of sensed radiation rate exceeds alarm radiation rate, if total dose information exceeds alarm dose information or if time-to-go, as computed, is less than alarm time-to-go information. Additional novel functions performed include determination of expected dose, first opportunity computations and decay time-to-go computations. In all these computations the processor is capable of extrapolating predicted radiation rates.

Claims

1. A personal radiation monitor comprising:

a radiation detector producing rate information related to real time radiation exposure rate to which said radiation detector is exposed,

a digital processor responsive to said radiation detector for integrating said rate information to maintain total dose information,

output means responsive to information provided by said digital processor for providing a manifestation of at least said rate and total dose information,

said digital processor including;

first means for repeatedly comparing said total dose information to dose limit information to produce dose-to-go information related to the difference between said total dose information and the dose limit information,

second means for, repeatedly, dividing said dose-to-go information by said rate information to produce and thereafter update time-to-go information related to time-to-go for the user to reach said dose limit, and

third means for controlling said output means for providing a manifestation of said updated time-to-go information.

2. The apparatus of claim 1 which further includes:

keyboard means responsive to user information and providing output signals indicative thereof,

said digital processor responsive to said output signals to derive said dose limit information.

3. The apparatus of claim 2 in which said digital processor further includes:

fourth means for comparing said time-to-go information with alarm time-to-go information and for providing an alarm signal to said output means when said time-to-go information is less than said alarm time-to-go information.

4. The apparatus of claim 3 in which said output means includes a visually perceptible display for said rate, total dose and time-to-go information and an audible signalling device operated by said alarm signal.

5. The apparatus of claim 3 in which said digital processor further includes:

means for storing an alarm rate,

fifth means for comparing said rate information with said alarm rate and for producing a rate alarm signal to said output means to operate an audible signal producing device if said rate information exceeds said alarm rate.

6. The apparatus of claim 3 in which said digital processor further includes:

fifth means for producing a dose alarm signal to said output means to operate an audible signal producing device if said total dose information exceeds alarm dose information.

7. The apparatus of claim 1 which further includes:

transceiver means responsive to an external source of information and providing output signals indicative thereof, and responsive to said digital processor for transmitting information signals to an external information sink,

said digital processor responsive to said output signals to derive said dose limit information.

8. The apparatus of claim 7 in which said digital processor further includes:

fourth means for comparing said time-to-go information with alarm time-to-go information and for providing an alarm signal to said output means when said time-to-go information is less than said alarm time-to-go information.

9. The apparatus of claim 8 in which said output means includes a visually perceptible display for said rate, total dose, and time-to-go information and an audible signalling device operated by said alarm signal.

10. The apparatus of claim 8 in which said digital processor includes:

means for storing an alarm rate,

fifth means for comparing said rate information with said alarm rate and for producing a rate alarm signal to said output means to operate an audible signal producing device if said rate information exceeds said alarm rate.

11. The apparatus of claim 8 in which said digital processor further includes:

fifth means for producing a dose alarm signal to said output means to operate an audible signal producing device if said total dose information exceeds alarm dose information.

22. The apparatus of any of claims 1, 13, 17 or 19 wherein:

said digital processor includes means for protecting said total dose information from manipulation by an operator or user.

12. A personal radiation monitor comprising:

a radiation detector producing rate information related to real time radiation exposure rate to which said radiation detector is exposed,

a digital processor responsive to said radiation detector for sensing and integrating said rate information to maintain total dose information, said digital processor including first means for storing a time parameter and at least one parameter indicative of a prevailing radiation decay rate,

said digital processor including second means for determining, based on said prevailing radiation decay rate, predicted dose information for a selected time in the future representing a dose that would be accumulated by a user exposed to prevailing radiation for the selected time, equal to said stored time parameter,

said digital processor further includes means to sum said total dose information with said predicted dose information, and

output means responsive to information provided by said digital processor for providing a manifestation of at least said sum of said predicted dose information and said total dose information.

13. The apparatus of claim 12 in which:

said digital processor further includes third means for repeatedly comparing said total dose information to dose limit information to produce updated dose-to-go information related to the difference between said total dose information and the dose limit information,

fourth means for dividing said updated dose-to-go information by said rate information to produce updated time-to-go information related to time-to-go for the user to reach said dose limit, and

fifth means for controlling said output means for providing a manifestation of said updated time-to-go information.

14. The apparatus of claim 13 which further includes:

keyboard means responsive to user information and providing output signals indicative thereof,

said digital processor responsive to said output signals to derive said dose limit information.

15. The apparatus of claim 14 in which said digital processor further includes:

sixth means for comparing said time-to-go information with alarm time-to-go information and for providing an alarm signal to said output means when said time-to-go information is less than said alarm time-to-go information.

16. The apparatus of claim 13 which further includes:

receiver means responsive to an external source of information and providing output signals indicative thereof,

said digital processor responsive to said output signals to derive said dose limit information.

17. A personal radiation monitor comprising:

a radiation detector producing rate information related to real time radiation exposure rate to which said radiation detector is exposed,

a digital processor responsive to said radiation detector for sensing said rate information, said digital processor including first means for storing a time parameter and at least one parameter indicative of a prevailing radiation decay rate, as well as a work area rate and a work dose parameter,

said digital processor including second means for determining a sum of;

(a) a first predicted dose based on said prevailing exposure rate and decay rate and an initially unknown time parameter,

(b) said work dose parameter,

said second means including means for determining said unknown time parameter by equating said work dose parameter to a calculated dose based on said time parameter and a work area rate equal to said stored work area rate but modified by said unknown time.

18. A personal radiation monitor comprising:

a radiation detector producing rate information related to real time radiation exposure rate to which said radiation detector is exposed,

a digital processor responsive to said radiation detector for sensing and integrating said rate information to thereby maintain total dose information, said digital processor including first means for storing a selected radiation dose limit parameter and at least one additional parameter indicative of radiation decay,

said digital processor including second means for determining, based on predictable radiation decay, a predicted time at which an accumulated dose, equal to said stored dose limit parameter, will be reached, said second means including means for obtaining a difference between said dose limit parameter and said total dose information and predicting said predicted time based on said difference, and

output means responsive to information provided by said digital processor for providing a manifestation of at least said predicted time information.

19. The apparatus of claim 18 in which:

said output means further includes default display means responsive to information provided by said digital processor for providing a manifestation of at least said rate and total dose information,

said digital processor further including;

third means for comparing, in real time, said total dose information to dose limit information to produce real time dose-to-go information related to the difference between said total dose information and the dose limit information,

fourth means for dividing said real time dose-to-go information by said rate information to produce real time, time-to-go information related to time-to-go for the user to reach said dose limit, and

fifth means for controlling said output means for providing a manisfestation of said real time, time-to-go information.

20. The apparatus of claim 19 which further includes:

keyboard means responsive to user information and providing output signals indicative thereof,

said digital processor responsive to said output signals to derive said dose limit information.

21. The apparatus of claim 19 which further includes:

receiver means responsive to an external source of information and providing output signals indicative thereof,

said digital processor responsive to said output signals to derive said dose limit information.