对标称K值为2的探头，检测缺陷已知的钢板对接焊缝，在仪器输入的K值距测量的实际K值间有不同偏差的情况下 ，分别得出缺陷测量结果，分析了K值偏差对缺陷定位定量相关参数的影响程度，对参加超声检测二级考试学员的疑问得出了确切的回答，K值测量时产生的正负0.04范围内的误差不影响最终成绩，可以作为考级人员K值测量的参考。

Using nominal K value of 2 to detect the given flaw of steel plant butt weld, the location and quantity parameter of the flaw in the case of inputting different K value with deviations were acquired. How the K value deviation was to affect the detection result was analyzed and questions by the candidates were answered. Deviation of ±0.04 for the K value shall not affect the grade of students and it will be a reference to candidates only.