Patent ID: 8044356
Filing Date: 2011-10-25
Classification: G01T

Abstract:
1. A survey meter for measuring a radioactive contamination caused in an inner surface of a pipe, the survey meter comprising: a rod-shaped light guide unit having a predetermined length, the light guide unit including a first light guide section including a fluorescent conversion material and a second light guide section including a transparent material, in which the first and second light guide sections are connected to each other at respective one end surfaces thereof; a reflecting portion connected to another end surface of the first light guide section; a photoelectric transfer unit, for outputting an electronic signal, connected to another one end surface of the second light guide section; a scintillator unit provided to a circumferential surface of the light guide unit in which the first and second light guide sections are connected to each other; a shielding member configured to transmit radioactive rays, block a light radiated from outside, and reflect a light within the scintillator unit; a pulse height discriminator for outputting a logic signal at a time when a pulse height value of the electronic signal outputted from the photoelectric transfer unit is higher than a threshold value; a counter unit for counting the logic signal outputted from the pulse height discriminator; a contamination judging unit for judging whether a radioactive contamination is caused or not on the basis of a value counted by the counter unit; and a display unit for displaying the value counted by the counter unit and a contamination judging result judged by the contamination judging unit.