| 摘要 |
<p>The sensor contains converters (2,3) from optical to electrical energy and vice-versa and also at least one electrical oscillator circuit (4) having a resonant frequency or Q value dependent on the value being measured. Optical energy in the form of pulses is fed to and from the sensor via an optical fibre. The pulse duration is shorter than the periodic time of the resonant oscillation. Alternatively, the optical energy is in the form of a sinusoidal signal. A light pulse impinges on an interceptor (2) of the sensor consisting of one or more photodiodes. The resultant voltage drives a current through the sender component (3), e.g. a l.e.d. The oscillating circuit (4) modulates this current so that the intensity of the emitted light varies according to the fading or resonant frequency of this circuit (4). The measured value can be for position location, power, pressure, liq. level, flow rate, temp., voltage, current, or a magnetic field.</p> |
