microSAM Total Field Magnetometer


Twinleaf has created a breakthrough, ultra-compact optical magnetometer with an integrated control unit. microSAM is a microfabricated total field optical magnetometer. Its small size and low power consumption enable a wide range of new precision magnetometer applications. Now in its second generation, microSAM 2 features half the volume and power consumption of the previous version, bringing the power consumption well under a watt. The sensor has a single axial dead zone, which is easy to avoid in most applications. Multiple sensors can be synchronized using synchronization units such as SYNC2, SYNC4, and SYNC7. Total system heading errors can be compensated when coupled with a vector magnetometer such as VMR.




Plug it in, and wait for the sensor to warm up. The status light blinks according to the sensor status:

Code Status Blink
0 Idle/off −_−_____−_−_____−_−_____ two short blinks
0 Idle/off (synchronized) −_______−_______−_______ one short blink
1 Cell heating −−−−____−−−−____−−−−____ long blinks
2 Laser heating/locking −_−_−_−_−_−_−_−_−_−_−_−_ short blinks
3 Spin locking −−−_−_−_−−−_−_−_−−−_−_−_ one long two short blinks
4 Locked and measuring −−−−−_−_−−−−−_−_−−−−−_−_ one long one short blink
4 Locked and measuring (synchronized) −−−−−−−_−−−−−−−_−−−−−−−_ one long

The status code is also reported as the status byte in the data stream:

  37 52912.193 252 4
  38 52911.398 253 4
  39 52911.901 252 4

In text mode, the first column is the sequence number that should be sequential; this is useful to make sure you aren't missing points. The second column is the total magnetic field in nanotesla. The third column is the signal amplitude. If the sensor is too close to the dead axis or in a very strong field gradient on your steel desk, the signal will be low; reposition or reorient the sensor to maximize this number to get the best results. The last column is the status code.


Firmware update: microSAM-R12-firmware-2019-09-17-8a7954.bin


microSAM, $7469.