| 摘要 |
The invention relates to a surveying apparatus, in particular tachymeter, laser scanner, profiler or laser tracker, comprising an electronic laser distance measuring module, which comprises an optical transmission channel and an optical reception channel for laser measurement radiation, wherein a variable optical attenuation unit for the laser measurement radiation is provided in the optical transmission channel and/or optical reception channel. According to the invention, light impinging on the attenuation unit is attenuated by means of liquid crystals. The attenuation unit comprises at least one polarizer, in particular comprising a polarization sheet, a liquid crystal shutter, in particular comprising nematic liquid crystals, having a variable transmission, a first analyzer, in particular comprising a polarization sheet. |
