Total posts : 45366
Regarding: “The question is how much over can you unintentionally be, before the field agent decides to issue an NOUO?” I will comment that it depends.
One factor would be the expected error of measurement for the field strength instrument. If, for example, the error of measurement at the field strength indicated is +/- 10% (a made up n number) then a true signal of 250 uV/m could indicate from 225 to 275 uV/m. A competent operator should know the error band and allow for it. Beyond that it would be a judgement call on the part of the inspector.
That being said, from Rich’s example even the lowest reading cited was no doubt well outside the expected error band exceeding the limit by a large factor and a challenge using the accuracy of the measurement would probably fail.
Some important points are made in Rich’s post. The power out of the transmitter does not guarantee a known field strength and cannot be relied on for compliance and that a very small power can easily produce a field strength which greatly exceeds the limit.