摘要 |
<p>A multi channel averaging circuit for use with an optical sensing system utilising back-scattered light for establishing the scattering profile along a fibre sensor, e.g. to determine the temperature distribution along the optical fibre sensor. The circuit comprises a number of connected in parallel, charge coupled devices (3-9) energised by a clock (10) and arranged to store successive elements of a signal waveform derived from the back-scattered light. The stored analogue signals are fed sequentially into the averaging circuit (11), sampled, and then digitised by an A to D converter (13).</p> |