| 摘要 |
PURPOSE:To ignore an instantaneously generated abnormal value and to prevent incorrect detection by comparing a value obtained by correcting the preceding value with a decision value while comparing a measured thickness value with the preceding value sequentially. CONSTITUTION:In accordance with a command from a synchronizing part 1, a transmission/reception part 3 applies a signal to a contact 6. The contact 6 makes an ultrasonic signal incident to a substance 5 to be tested through a contact medium 7. A reflected signal from the surface of the contact 6 is turned to a signal 10 by the transmission/reception part 3, a reflected signal from the bottom of the substance 5 to be tested is turned to a signal 11 by a receiving part 8 and these signals 10, 11 are inputted to an operation part 12 respectively. The operation part 12 counts the signals 10, 11 counts the time width and then outputs a thickness measured result 14. The result 14 is compared with a preceding value 16 by a preceding value comparing part 15, the compared result 17 is sent to an addition/subtraction part 21 through an addition/subtraction control part 18. A correction value 23 is added or subtracted to/from the preceding value and the result 24 is compared with a decision value 29 by a comparing part 27 through a holding part 25 to obtain a thickness-decided and compared result. |
