| 摘要 |
The invention refers to a method of and device for continuously measuring the thickness of electrically conductive moving sheet material consisting in providing an eddy current type thickness gauge which is affected by the thickness and temperature of the sheet material, a rotatably mounted tubular metallic body of essentially cylindrical shape which is longer than the width of the sheet material and is in contact with the whole width of the sheet material whereby the sheet material and the metallic body both acquire the same temperature, electrical means are provided to sense the temperature of the metallic body giving an electrical signal and means are provided to apply said signal to the eddy current gauge to compensate automatically for the effect of temperature variations of the sheet material on the thickness measurement. In one example of the invention the electrical means to sense the temperature of the metallic body consists of two coils of which the primary carries alternating current, a disc shaped body which is in thermal contact with said metallic body is positioned between the two coils and the secondary voltage is thus a function of the temperature of the metallic body. Since this latter means is identical with the means used in the eddy current gauge for thickness measurement, the said secondary voltage follows the same law as far as temperature dependence is concerned as the eddy current gauge and therefore the temperature compensation is exactly correct over the whole temperature range.
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