| 摘要 |
PURPOSE:To obtain an A/D converter which achieves a shortening of time required for the correction of conversion errors. CONSTITUTION:X rays generated from a sample 1 with the irradiation of an electron beam are detected with an X-ray detector 2. An X-ray signal from the X-ray detector 2 is converted into a digital signal with a conversion system 3 comprising an amplifier and an A/D converter. This signal is sent to a signal processing means 5 of a computer 4 and undergoes a computer processing. The signal also is sent to an error operating means 6 to determine a gain error (1-g) and an offset error (-z) of the conversion system 3. The errors thus obtained are supplied to a divider 7. A conversion coefficient operating means 8 determines a conversion coefficient based on the signal from the error operating means 6 and supplies the conversion coefficient obtained to the divider 7. The divider 7 divides the signal from the error operating means 6 by the conversion coefficient from the conversion coefficient computing means 8 and the results are supplied to the conversion system 3. |
