But in the case of detecting magnetic fields, there is a problem: The color centers can only detect magnetic fields that are aligned in the same direction as the sensors. Thus, a practical magnetometer needs to contain many sensors, placed at different alignment angles, which makes them difficult to build and use and with an accuracy limited to the number and position of the sensors used. Furthermore, the fact that they are rigid (diamond is the hardest natural material known) means that they cannot conform to the samples being studied.
