| 摘要 |
<p>PURPOSE:To eliminate the electric noises of a voltage to be metered thereby to improve the metering accuracy by using an electrooptical crystal, which has such a construction that its portion for detecting a high voltage is electrically inconductive. CONSTITUTION:A projected beam from a light source 3 is converted through a lens 4 into a paralled beam, which is then subjected to linear polarization by means of a polarizing element 5. At this time, the angle between the polarizing plane of the element 5 and the optical axis of an electrooptical crystal 6 is preset at an angle to guide the projected beam into the crystal 6. Since the crystal 6 changes the polarized light component in the preset direction of the beam in accordance with the voltage level to be impressed upon the electrode 7, the intensity of the beam of an optical detecting element 9 is varied with the voltage applied when the beam transmitting through the crystal 6 is observed through the element 9. In the beam having been transmitted with there is no electric field in the crystal 6 is set to become the linear polarized beam having a polarizing plane at a right angle with respect to the element 9, the output of an optical detector 10 is increased with the increase in the voltage applied to the electrode 7 of the crystal 6.</p> |
