PURPOSE: To estimate the average temperature of the section of a cable with high precision, by determining the average temperature of the section through correcting the average value of measured temperatures in the circumferential direction of the cable on the basis of a correction value obtained by experiment or analysis.
CONSTITUTION: Measurements are performed by a contact thermometer, etc., at more than one point on a cable surface in the circumferential direction to measure average temperature Ts. During a cable laying period, the difference between the respective average temperature for the surface and the section of the cable is obtained with time by experiment, and a primary correction value α1 which corresponds to a curve determined by the difference between the sectional area of the cable and the secular average temperature difference is added to make the primary correction of the temperature Ts. Further, secondary correction value α2 obtained by multiplying the difference between a standard ambient temperature determined with time and a measured ambient temperature by a coefficient β varying in accordance with the difference in sectional area is added to correct the temperature Ts, thus measuring the average temperature of the cable section with high precision.
TOUI HIROSHI
ARAYA TOORU
MINATO RICHIYUU
