ETS-Lindgren HI-4456 Isotropic Electric Field Probe (Archived) - Manual (Page 24)

HI n 4456 Manual Page — 19
the processor receives all the zero-field values, it stores
them in a special register; these values are subtracted
from all subsequent measurements. Therefore, a probe
which is zeroed while it is not in a zero field environment
will give erroneous readings.
Archived 4/2/10