This combination offers the ability to distinguish if the offending field is AC or DC, and whether it is electric, magnetic or microwave. If you want to be able to distinguish a specific microwave signal from the background, your will need a spectrum analyzer. The RF Signal Strength Analyzer will tell you which signals are present, what their frequencies are, and give you an idea of how strong each signal is. By watching the analyzer, you may be able to correlate the appearance of a specific signal with the onset of your symptoms. This type of information will help you zero in on the source and be a great help to law enforcement authorities.
All meters have a range of exactly zero feet.
What distinguishes one meter from another is the sensitivity. A gaussmeter with a sensitivity of 0.1 mG is more sensitive than a meter which can only detect down to 1.3 mG. While the meter which is more sensitive can be successfully used further away from the source of the field, it is still only measuring the field at the location of the meter. Without knowing a great deal about the nature of the source, it is impossible to determine at what distance a given meter will begin to detect its field. What you can do is easily compare the minimum sensitivity of one meter to another. This specification is given in the description of most meters.