| 摘要 |
Disclosed is a measurement apparatus for measuring physical quantity, such as temperature, pressure etc., and providing corresponding measurement data suitable for transmission to a remote central location. The physical quantity being measured is first converted to a frequency signal, either directly by an appropriate transducer or by a combination of an appropriate transducer and appropriate converter. Counters are then used to convert the frequency signal to a corresponding digital quantity. An appropriately programmed digital processor is then used to perform processing operations on the digital quantity to derive the measurement data. In one embodiment, the apparatus includes an optical transceiver for converting the measurement data into corresponding optical signals for transmission via an optical fiber to a central processor. The optical transmission system between the measurement apparatus and the central processor includes provisions for facilitating the detection and diagnosis of failures in the optical components of the system. In another embodiment the measurement data is converted to corresponding current signals for transmission via a conducter to a remote central location. |
