| 摘要 |
A light source, two radiation conducting systems, a measurement probe, a photo-detector (5) and computing and display units are provided. A lamp or a pulsed laser may be used as light source, and the radiation from conducting system may comprise mirrors or optical fibres. If it is possible to direct light from the source straight to the probe, the system may be eradicated. The probe normally comprises a lens system, a linear polariser, a circular polariser, a Pockel cell, and a further linear polariser and lens system. The high voltage on the corresp. electrode is connected capacitively to the one electrode of the Pockel cell through a capacitance, whilst the other electrode of the cell is connected to a reference potential, e.g. earth. The amplitude of the high voltage affects the intensity in the photo detector, the output of which is a dimension of the AC voltage. |
