| 摘要 |
PURPOSE:To improve the detecting precision by constituting a titled machine of an adjusting circuit means for adjusting a percussive detecting period of an electric wave form of percussive detection and a percussive detecton circuit means capable of performing at several points or more of at least two points of percussive detecting positions. CONSTITUTION:A detection synchronizing signal adjusted so that the percussive detection is performed at several points or more of at least two points by a voltage oscillated by an oscillation circuit 4 or a time adjusting circuit 5 is generated and is entered to a coil 9 for percussive detection using an electric hammer through monostable multivibrator circuits 6a and 6b, an output synthesizing circuit 7, a sensor driving circuit 8 to perform the percussive detection of a case 2. The result is adjusted through a vibration sound detector 10, an amplifier circuit 17 so that it attains to a frequency most suitable to quality discrimination and max. wave crest value by filters 11a and 11b, and the quality is compared by comparator circuits 13a, 13b. A signal is sent to an operation duty circuit 14 basing on the compared result of the circuit 13. In case of inferior articles, they are rejected after a fixed time or fixed numbers and an output of a detection control circuit 15 is generated simultaneously. |
