THICKNESS MEASUREMENT DEVICE AND THICKNESS MEASUREMENT METHOD

To provide a technique which can accurately correct the thickness of an inspection object on the basis of the temperature of the inspection object.SOLUTION: An excitation part 41 applies an excitation current to an excitation coil 11 to induce an eddy current in an inspection object 9. An eddy current detection part 42 detects the eddy current of the inspection object 9 through a detection coil 12. An inspection object temperature acquisition part 45 acquires an inspection object temperature Tm. A thickness calculation part 61 calculates a thickness d of the inspection object 9 on the basis of duration τ of the eddy current detected by the eddy current detection part 42. A correction part 62 corrects the thickness d on the basis of the inspection object temperature Tm when the eddy current is detected by the eddy current detection part 42 and a correction formula that has an item concerning the inspection object temperature Tm. The item concerning the inspection object temperature Tm of the correction formula has a correction coefficient A. The correction coefficient A is calculated on the basis of multiple pieces of measurement data of the inspection object temperature Tm and the elapsed time Δt from a reference time t0 to a time t when each measurement data is acquired.SELECTED DRAWING: Figure 1 【課題】被検物の温度に基づいて、被検物の厚さを精度良く補正することができる技術を提供する。【解決手段】励磁部４１は、励磁コイル１１に励磁電流を印加して被検物９に渦電流を誘起させる。渦電流検出部４２は、被検物９の渦電流を、検出コイル１２を介して検出する。被検物温度取得部４５は、被検物温度Ｔｍを取得する。厚さ算出部６１は、渦電流検出部４２によって検出された渦電流の継続時間τに基づいて被検物９の厚さｄを求める。補正部６２は、渦電流検出部４２によって渦電流が検出された時の被検物温度Ｔｍと、被検物温度Ｔｍに関する項を有する補正式とに基づいて、厚さｄを補正する。補正式の被検物温度Ｔｍに関する項は補正係数Ａを有する。補正係数Ａは、被検物温度Ｔｍの複数の測定データと、基準時ｔ０から各測定データが取得された時ｔまでの経過時間Δｔとに基づいて求められる。【選択図】図１