Survey meter

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.