Various measurements were taken to eliminate experimental uncertainties. Both the large and small antennas were used. The geometry of scattering objects in the lab was altered. The effect of varying the transmitter power was investigated, to see if the detector calibration was accurate. Despite the variability of the path loss from measurement to measurement, the results of this experiment, when averaged, are reasonably consistent.
Various factors contribute to the path loss.
We have discussed above the various ways that energy could get from the transmitter to the receiver without going through the human. The absorber screens were necessary, and it is felt that they were reasonably effective in stopping most of the leakage as, in the raw data plots above, the ripple in the insertion loss due to resonant effects is largely absent. It is possible to estimate the wave impedance mismatch at the human-air boundary by the following argument. The human body, for microwave purposes, is mostly salty water. However, the data from the experiment yields some thoughts of interest to the amateur.