SCANNING TYPE MEASURING DEVICE

PURPOSE:To measure physical quantity without errors in a short ime, by memorizing a compensating quantity based on the relative misalignment of the position of the measuring device as digital data, and obtaining the quantity to be measured by digital operation. CONSTITUTION:Under the state an object to be measured 45 is not placed between a radiation source 13 and a detection part 17, at first, a measuring part 60 is moved from one end of a moving path to the other end by a motor in the advancing direction (f). At a specified time interval, the signals from the detection part 17 are inputted into a memory 85, through an AD converter 73 and switches 63 and 67. Meanwhile, the detected position signals from a position detector 43 are inputted in a memory 85 through an AD converter 79 and switch 69. In the case of the backward direction (r), the switches 67 and 69 are switched by a controller 61, and a measuring position error quantity pattern is stored in a memory 87. Under the state the object to be measured is placed, the measured signal 75 of the AD converter 73 and compensating signal 89 or 91 of the memory 85 or 87 are inputted to a computation processor 95, and the error compensated thickness is displayed 57.