| 摘要 |
An instrument for measuring thin layer thickness according to the X-ray fluorescence method. Such device has means for observing the area of the surface of the layer through which the geometrical central axis of the X-rays pass, and a table for supporting objects which are to be measured, which has a portion defining a cut-out around the geometrical central axis. The device has illuminating means for lighting the surface through the cut out. An electronic eye is located in the path of light rays from the illuminating means on the ocular side. An image screen is controlled by the electronic eye. Depressor means is provided above the cut-out and has a pressure-applying face adapted for movement between an upper and a lower position, the upper position being at least high enough that the object to be measured can be pushed between the pressure-applying face and the table. The pressure-applying face is adapted to apply force when in the lower position to press the object to be measured against the top of the table and hold the object in a non-positive manner. Switchable means is provided for moving the depressor means in the upper and the lower positions. The pressure-applying face is located about the geometrical central axis of the X-rays, the distance between the pressure-applying face and the geometrical central axis being far less than the distance from the geometrical central axis to the edge of the table. The cut-out in the table has a very much larger area than the cross-section of the X-ray beam.
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