| 摘要 |
PCT No. PCT/FR90/00467 Sec. 371 Date Mar. 18, 1991 Sec. 102(e) Date Mar. 18, 1991 PCT Filed Jun. 26, 1990 PCT Pub. No. WO91/00413 PCT Pub. Date Jan. 10, 1991.A dynamometric measuring device for a drill pipe which includes, firmly attached to the rotating pipe, sensors disposed in a groove on the pipe and electronics for conditioning the signals supplied by the sensors. The measurement signals are transmitted by a commutator-fixed brush assembly to a fixed, non-rotating part. By providing follower-amplifiers of very low output impedance on the commutator, rotating, portion of the assembly and follower-amplifiers of very high input impedance on the fixed brush side of the assembly, the transmission of signals is carried out at zero current. To assure high quality signal analysis, a separation circuit on the fixed brush side of the assembly separates the DC and AC components of the signal prior to transmission to the surface.
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