Method and device for measuring an electrical alternating quanity with temperature compensation

US5811964A · kind A · utility

Assignee

• Siemens Aktiengesellschaft · DE

Inventors

• Thomas Bosselmann · Erlangen, DE
• Peter Menke · Erlangen, DE
• Joachim Niewisch · Nuremberg, DE

Key dates

• Filing date: Apr 1, 1996
• Grant date: Sep 22, 1998
• Expiry date: Apr 1, 2016

Classification

• Technology area (CPC G): Physics
• CPC primary: G01R15/246
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

A polarized measuring light is provided to a sensing means under the influence of an alternating electrical quantity, the polarization of the measuring light changing as a function of the alternating electrical quantity. After passing through the sensing means, the measuring light is split into two differently polarized partial light signals, which are then converted into electrical intensity signals S1 and S2. An intensity-normalized signal P=(S1-S2)/(S1+S2) is then formed. A temperature-compensated measured signal can then be derived from the alternating signal component PAC and the direct signal component PDC of the intensity-normalized signal according to the equation S=(a*PAC+b*1)/(c*PDC+d*1). The temperature sensitivity can thus be reduced by a factor of ten.