1. R ADIATION S AFETY I NSTRUMENTS Pawitra Masa-at 4937092 SIRS/M

4. Gas-Filled Detectors

6. Gas-Filled Detectors wall fill gas R Output or Anode (+) Cathode (-) End window Or wall A

7. I ; Ionization chamber region P ; Proportional region GM ; Geigur-Mueller region

10. Ionization Chamber HV + - Negative ion Positive ion 1234 Electrometer The response is proportional to ionization rate (activity, exposure rate)

12. Portable ion chamber survey instrument Contamination Survey meter

19. Geiger Müller-tube principle Knoll - + - A single incident particle cause full ionization

21. pocket dosimeter survey meter Area Alarm Monitor

23. Thermo-luminescence Dosimeter (TLD)

27. TL Process Valence Band (outermost electron shell) Conduction Band (unfilled shell) Phosphor atom Incident radiation Electron trap (metastable state) -

28. TL Process, continued Valence Band (outermost electron shell) Conduction Band Phosphor atom Thermoluminescent photon - Heat Applied

31. Thermoluminescence dosimeter : area monitoring , Personnel radiation monitoring (Courtesy Bicron.)

33. Optically stimulated luminescence (OSL)

36. Optically Stimulated Luminescence dosimeters (Courtesy Laudauer.)

38. Thank you