A1258150651PBwvZ

1
Monitor 4 Geiger Counter
2
Using the Meter

• 3 Indicators
• Meter CPM mR/hr
• X1, X10 X100
• LED
• Speaker
• Battery test
• Computer cable

3
About the GM Meter

• Measures ?, ? and ?
• How it works - radiation ionizes atoms in the
  gas tube in the detector. Under high voltage
  more ions form and produce an electrical pulses
  that produces an audible and visual indication
• Number of pulses is proportional to the strength
  of the radiation
• Screened mica window for ?, ? and ?
• Back for High energy ? and ?

4
Classroom Exercise
Background Radiation and Personal Dose

• Count the LED flashes or the audio beeps for five
  minutes
• How can you increase the measurement accuracy?
• Estimate your personal radiation exposure

5
Classroom Exercise
Inverse Square Relationship

• Measure radiation at several distances from a
  source

• Correct for background radiation

• Estimate the dose based on inverse
  squares  I1 (Rx)2 Ix (R1)2

6
Classroom Exercise
Calculate the dose rate at a given distance from
the source. Radiation Dose Rate at Distance r
Effective Area of Body 4 ?r2 Dose Rate
1 mrem/hr 0.0003 mrem/hr
1.4 X 0.25 4? (10)2
r 10 m
1.4 m
1 mrem/hr
0.25 m