| 摘要 |
A pressure sensing system that is relatively immune to EMI. The system comprises a sensor and a controller linked to one another by a fiber optic cable. The sensor includes an electronic pressure transducer, and means for converting an optical power signal received from the controller via the fiber optic cable into DC electrical power for the transducer. The transducer produces an electronic output signal that encodes the pressure, and this output signal is converted into a corresponding optical output signal that is transmitted to the controller along the fiber optic cable. A preferred pressure transducer is a vibrating crystal pressure transducer, the output signal of which is converted to electronic form at the controller, and demodulated by a counter. The power signal is preferably a time invariant, and not a function of the output signal.
|
