ETS-Lindgren HI-2200 RF Survey Meter - Manual (Page 40)

40 | Application
The HI-2200 provides a useful feature described as Spatial Averaging. Safety
standards often specify maximum exposure levels in terms of Whole-Body
Average values. This means that the exposure levels must be averaged over the
whole body space occupied by the subject. This is accomplished by slowly
moving (at a constant rate) the probe head through the space occupied by the
subject (with the subject not present) and recording the average value during this
movement. The Spatial Averaging function automatically calculates the averages
as the probe is moved through this space. As has been noted, the RMS average
values should be used for higher frequencies (typically above 100 kHz). The
RMS average is the default selection for the spatial averaging function and
running average values are displayed and recorded.
When in the Spatial Averaging mode, the running average is the primary value
displayed. At the end of a spatial average measurement, the final, whole-body
average is displayed as the primary value and the MAX value is the highest
reading observed during the measurement. The spatial average data logged into
data files includes the spatial average, the maximum value, and the individual
values measured at one-second intervals.