| 摘要 |
<p>The tool (1) has a radiation impermeable housing (2) provided with a base (3) and a front surface (4) that is formed opposite to the base. A break-through (6) is arranged in an aperture plate, an aperture slot, a cross screen and a projection surface (7) that is arranged close to the base in the housing. The break-through extends between the base and the front surface, and a marking (10) is aligned with a middle axis (13) of the break-through of the front surface. A viewing window (9) is assigned to the projection surface in a side wall (8) of the housing. The break-through is formed in circle, line, or in cross shape.</p> |
