X-ray thickness gage

Abstract

The purpose of this invention is to provide an X-ray thickness gauge in which, using a simple configuration, measurement error due to temperature drift in the amount of radiation delivered by said X-ray thickness gauge after thickness calibration has been performed can be corrected, even while in the process of performing a measurement. Said X-ray thickness gauge (100) is provided with the following: an X-ray generator (1) provided with both a cooling unit (1b) that uses a cooling medium to cool an X-ray tube (1a) and a power-supply unit (1c) that supplies power that is applied to said X-ray tube; a detector (5) that detects delivered detection radiation that has passed through an object (4) being measured; a calibration device (2) provided with a thickness reference sample; and a computation unit (6) that references a calibration table to determine the thickness of the object being measured. This X-ray thickness gauge is also provided with a temperature sensor (7) that measures the temperature of the cooling medium. The computation unit is provided in advance with a temperature-correction table from which a detection-radiation delivery amount corresponding to the difference between the temperature of the cooling medium during calibration and the temperature of the cooling medium during a measurement can be determined. The computation unit references said temperature-correction table to determine the amount of detection radiation to deliver and references the abovementioned calibration table to determine the abovementioned thickness.