| 摘要 |
PURPOSE:To dispense with an operation for correction of a measuring error on the basis of the temperature and quality of a material to be inspected. CONSTITUTION:Data on a frequency division ratio corresponding to the temperature and quality of a material 10 to be inspected are stored in a storage part 58. Based on the temperature and quality of the material 10 inputted from a temperature input part 59 and a quality input part 60 respectively, the data on the frequency division ratio corresponding to the temperature and the quality are read out from the storage part 58. A divider 56 divides the frequency of an output pulse of a pulse generating part 57 by the frequency division ratio specified by the data on the frequency division ratio and outputs a divided frequency pulse obtained thereby to a plate thickness measuring part 54. The plate thickness measuring part 54 detects a distance of propagation of an ultrasonic wave by counting the divided frequency pulse in a period from the time point of reception of a reflected wave u-1 to the time point of reception of a reflected wave u-3 and executes an operation of multiplying the distance of propagation by a corrected sound velocity. |
