PLASTIC RESIN PIPE DETECTOR

摘要

PROBLEM TO BE SOLVED: To judge the presence or absence of a plastic resin pipe within an embedded gas supply metal pipe. SOLUTION: The gas supply metal pipe DP is irradiated with fast neutrons from a neutron source and neutrons are reflected/transmitted by a plastic resin pipe PE when the plastic resin pipe PE is inserted into the gas supply metal pipe to lose energy to become thermal neutrons. The thermal neutrons are counted for a definite time by a thermal neutron measuring module and the correction of attenuation due to natural decay based on a calender time RTC is performed and the correction value is compared with a predetermined threshold value to judge the presence or absence of the plastic resin pipe.