| 摘要 |
<p>PURPOSE: To measure an electric current with high accuracy even under a bad condition by airtightly inserting a rod lens into the through hole of an airtight optical connector so that light can be introduced to an arithmetic and output section. CONSTITUTION: A rod lens 29 made of low-strain glass is inserted into a through hole 19 and fixed with an adhesive 20. Since the low-strain glass which is optical glass produced by eliminating residual stresses from the inside of the glass by performing annealing, etc., is used for the lens 29, the occurrence of the double refraction of light can be suppressed to an extremely low level. Since the rod lens 29, in addition, is formed by uniting a lens and glass rod in one body, excellent optical coupling can be obtained when the optical axis of the lens 29 is aligned with that of a capillary section 22, because light is condensed to an optical fiber 23. In addition, the lens 29 has a high vibration resistance and impact resistance. When a silicone rubber adhesive having a Young's modulus of 0.05-100 kg/mm<2> is used as the sticking means between the lens 29 and connector 8, the accuracy of an optical current transformer can be improved further, because the impact, vibration, thermal stress, etc., impressed upon the transformer are absorbed by the elasticity of the adhesive.</p> |
