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United States Patent | 6,429,646 |
Han | August 6, 2002 |
The invention relates to a method for calibrating the initial sensitivity of the eddy current roll-flaw detecting apparatus and an eddy current roll-flaw detecting apparatus which can be calibrated by the method. The method comprises the following steps: a) detecting an artificial defect sample to obtain a first vector; b) generating an analogue artificial defect signal; c) adjusting the analogue artificial defect signal to make it equal the first vector; and d) inputting the analogue artificial defect signal into the eddy current roll-flaw detecting apparatus, and adjusting the eddy current roll-flaw detecting apparatus to enable it to give a warning, wherein steps a) and c) are both implemented by means of the impedance analyzing unit having the function of displaying the impedance vector built in the eddy current roll-flaw detecting apparatus. The eddy current roll-flaw detecting apparatus comprises an impedance analyzing unit having the function of displaying the impedance vector, a modulation analyzing circuit and a warning circuit.
Jun 26, 1997 [CN] | 97112564 A | |||
Current U.S. Class: | 324/202 ; 324/240 |
Current International Class: | G01N 27/90 (20060101); G01R 035/00 () |
Field of Search: | 324/220,221,225,237,238,240,241,242,243,261,262,525,202,234,239,601 |
5334934 | August 1994 | Viertl |
A2194002 | Apr., 1995 | CN | |||
A1114747 | Jan., 1996 | CN | |||
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