what is the strength of the field at the source?
• at what rate does the field decrease with distance (1/d, 1/d, 1/d etc.). • what is the pattern of radiation from the source? (You may remember that the magnetic field is concentrated at the poles of a magnet. Some sources may have symmetrical field patterns, some may not.) 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.
