At present, hole trajectory azimuth Angle is measured mainly with magnetism sensor, but which is restricted by magnetic field and the metal tube around the surveying equipment.

目前的井眼轨迹方位角测量技术主要靠磁通门传感器，这种技术受地磁场及测量体周围金属管体的制约。

youdao

As a material highly sensitive to the environment, graphene could act as a sensor with a single device measuring strain, gas, magnetism or pressure.

BBC: Is graphene really a wonder-material?