Design of a digital gauss meter for precision magnetic field measurements

The design of a precision gauss meter for measuring magnetic fields is pres ented. The instrument utilizes a Hall element probe as a transducer and fea tures an analog front end capable of amplifying de and ac signals. A 16-bit analog-to-digital converter interfaces the analog section to a microcontro ller-based digital section which corrects nonlinearities in the Hall elemen t probe as well as gain errors in the amplifiers. The specifications called for 0.25% de accuracy and an ac bandwidth of 10 kHz, SPICE models were use d to determine the frequency response, noise characteristics, and temperatu re effects of the Hall element probe and the analog section, Finally, the a nalog section and the Hall element probe were calibrated separately and con figuration information was created for storage in EEPROM memory.