System for monitoring and analyzing field energy exposure

• US 5,440,232 A
• Filed: 12/06/1993
• Issued: 08/08/1995
• Est. Priority Date: 12/06/1993
• Status: Expired due to Fees

• Current Assignee: United States of America Represented By Secretary of The Navy Chief of Naval Research Office of
• Original Assignee: the united states of america as represented by the secretary of the navy
• Inventors: Scarzello, John F., Feaga, Adam C., Lenko, Daniel S.
• Primary Examiner(s): O'Shea, Sandra L.
• Assistant Examiner(s): Phillips, Roger
• Application Number:
  US08/186,711
• Time in Patent Office: 610 Days
• Field of Search: 324/247, 324/244, 324/258, 324/260, 328/150, 328/151, 307/309, 364/576
• US Class Current: 324/247
• CPC Class Codes: G01R 29/0857 Dosimetry, i.e. measuring the time integral of radiation intensity; Level warning devices for personal safety use nuclear radiation dosimetry G01T

Abstract

A portable electromagnetic field exposure dosimeter includes a triaxial fite-loaded coil sensor, a group of amplifiers and bandpass filters, a data control board, and a computer. The triaxial sensor receives electromagnetic radiation along three orthogonal axes for measurement which is channelled through a group of amplifiers and then bandpass filtered into three frequency signal ranges. One frequency range corresponds to exposure at 60 Hz and two of its harmonics. The second frequency range corresponds to high frequency pulsed energy. The third frequency range reflects body motion of a tested individual. The data control board converts such filtered signals into digital code and controls the flow of the converted data to random access memory and to the computer. The computer performs a Fast Fourier Transform on the converted data from the 60 Hz frequency range and then stores or displays the analyzed data as a function of frequency and time. The computer also stores or displays the data from the other two frequency ranges.

Claims

1. Apparatus for monitoring and analyzing exposure to ambient energy, including:

sensor means for measurement of the ambient energy along plural axes, amplifier means connected to the sensor means for processing said measurement of the ambient energy as electrical signals generated along said axes within different frequency ranges respectively corresponding to exposure of the sensor means within a field of the ambient energy, bandpass filter means connected to the amplifier means for simultaneously channeling the electrical signals processed by the amplifier means within the different frequency ranges; and

data processing means connected to the bandpass filter means for correlating the processed electrical signals simultaneously channeled by the bandpass filter means into exposure data respectively corresponding to the different frequency ranges associated with said field of the ambient energy, said amplifier means comprising two series connected low pass amplifying filters through which the electrical signals from the sensor means is processed, said bandpass filter means comprising;

two high pass filter stages through which the processed electrical signals within two of the different frequency ranges are respectively channeled to the data processing means from the amplifier means, a third high pass filter stage connected to the data processing means and a low pass filter stage connected in series between said third high pass filter stage and the amplifier means through which the processed electric signals within a third of the different frequency ranges is channeled to the data processing means.

2. Apparatus for monitoring and analyzing exposure to ambient energy, including:

sensor means for measurement of the ambient energy along plural axes, amplifier means connected to the sensor means for processing said measurement of the ambient energy as electrical signals generated along said axes within different frequency ranges respectively corresponding to exposure of the sensor means within a field of the ambient energy, bandpass filter means connected to the amplifier means for simultaneously channeling the electrical signals processed by the amplifier means within the different frequency ranges; and

data processing means connected to the bandpass filter means for correlating the processed electrical signals simultaneously channeled by the bandpass filter means into exposure data respectively corresponding to the different frequency ranges associated with said field of the ambient energy,

said bandpass filter means comprising two high pass filter stages through which the processed electrical signals within two of the different frequency ranges are respectively channeled to the data processing means from the amplifier means, a third high pass filter stage connected to the data processing means and a low pass filter stage connected in series between said third high pass filter stage and the amplifier means through which the processed electric signals within a third of the different frequency ranges is channeled to the data processing means.

3. A radiation dosimeter comprising:

transducer means responsive to ambient electromagnetic radiation for producing an electrical signal, including three ferrite-core coil sensors; and

circuit means connected to said coil sensors for amplifying and filtering the electrical signal within three predetermined frequency ranges of radiation exposure respectively measuring high frequency at 60 Hertz, pulse radiation characteristic and human body motion,

said circuit means including;

a first low-pass amplifying filter connected to the coil sensors;

a second low-pass amplifying filter connected to the first low-pass amplifying filter;

a first high-pass filter connected to the second low-pass amplifying filter;

a second high-pass filter connected to the first low-pass amplifying filter;

a third low-pass filter connected to the first low-pass amplifying filter; and

a third high-pass filter connected to the third low-pass filter.