美国通用汽车公司正在研制一种能直接测量扭矩的微型磁性传感器。这种扭矩传感器可以检测承受扭转载荷的球墨铸铁曲轴由于机械应力变化而引起的磁导率变化。尽管这不是什么新的原理,但是这种传感器仅需占用曲轴22mm 长的空间,传感器与曲轴之间保持1mm 的间隙,这种紧凑的传感器中只有一个简单的感应线圈和四个耦合线圈。 General Motors Corp. of America is developing a miniature magnetic sensor that measures torque directly. This torque sensor detects changes in permeability due to mechanical stress on ductile iron crankshafts subjected to torsional loads. Although this is not a new principle, the sensor takes up only 22 mm of space on the crankshaft and a 1 mm gap between the sensor and the crankshaft. This compact sensor has only one simple induction coil and four coupling coils.