| 摘要 |
PURPOSE: To eliminate the effect of temperature gradient in a liquid and the effect of absolute temperature by arranging at least a pair of thermocouples in a permanent magnet type probe tube for measuring the velocity in a region insusceptible to the magnet. CONSTITUTION: Thermocouples 1-4 are arranged in a permanent magnet type probe tube for measuring the velocity which detects the velocity component E21 of a signal voltage proportional to the current velocity from the voltage between two points of a field generated in a conductive liquid when it flows in a direction different from the direction of the field. Assuming the temperature difference between measuring points isΔT, the Al and Cr electrodes are A, B and the liquid metal is N, the potential difference between the electrode taps can be represented as follows; voltage U21 A=velocity component E21 +ΔT21 (SN-SA), voltage U21 C=E21 +ΔT21 (SN-SC), velocity component E43 A=ΔT43 (SN-SA), and voltage U43 C=ΔT43 (SN-SC). Consequently, the signal voltage E21 is represented by U21 A- U21 C×(U43 AU43 C)}/(U43 A/U43 C) which depends only on the velocity.
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