| 摘要 |
A single-wire time-domain reflectometer (TDR) combines the best performance features of prior art "electronic dipsticks" in a high accuracy implementation that allows tank penetration though a small opening. A wire-horn structure is employed to launch TDR pulses onto a single wire transmission line, wherein the horn wires can be flexed inwards so the dipstick structure can be inserted through a small tank opening. Once inside the tank, the horn wires flex to their normal state to provide a controlled reference reflection while simultaneously providing high coupling efficiency to the dipstick. The TDR system determines the fill-level of a tank by measuring the time difference between a reflection created at the wire-horn, which all is at the top of a tank, and a reflection from a material in the tank. The TDR employs automatic time-of-peak (TOP) detectors and incorporates a 2-diode sampler, a low-aberration pulse generator, and a 0.001% accurate timebase.
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