  The KArlsruhe TRItium Neutrino experiment (KATRIN) aims to measure the
electron neutrino mass with an unprecedented sensitivity of 0.2 eV/c2, using b
decay electrons from tritium decay. For the control of magnetic field in the
main spectrometer area of the KATRIN experiment a mobile magnetic sensor unit
is constructed and tested at the KATRIN main spectrometer site. The unit moves
on inner rails of the support structures of the low field shaping coils which
are arranged along the the main spectrometer. The unit propagates on a
caterpillar drive and contains an electro motor, battery pack, board
electronics, 2 triaxial flux gate sensors and 2 inclination senors. During
operation all relevant data are stored on board and transmitted to the master
station after the docking station is reached.
