Hall Probe Calibration

The calibration procedure of Hall sensors in the Magnet Section Measurement Lab (HP hutch, WMHA) is almost fully automatized. Practically the only requirement for the operator is to exchange the NMR probes (#1 ... #5) as the field in the Bruker magnet varies during the scanning from −2 to +2 T.

The Metrolab PT 2025 NMR Teslameter must be connected over the GPIB bus to the network (acsmm2 box). For the program <mmmgui> to be able to communicate with the NMR teslameter, the device must be put in the automatic mode (the corresponding button on the instrument must be pushed IN).

With the NMR probes #3, #4 and #5 the PT 2025 can find the NMR signal and lock to it while in the remote/search mode (LED is ON). For the older probes #1 and #2 this is not always the case since the NMR signal is rather weak and it might be neccessary to find the NMR signal with an oscilloscope. During the search the PT 2025 must be in the local mode (LED is OFF) which if neccessary can be set from within the program <mmmgui>.

Here is a table to help to search for the NMR signal: