If the receivers built in tone measures 80db how could it be inaccurate compared to 80db with the avia? I understand that the two different sources might be different volumes, but if the are the same relative to themselves what difference does it make? Example: you weigh youself everyday at home and it is 150lbs. At the Dr. office it is 155 lbs every time. One of the scales is off, but it dosen't make any difference as long as you pick which scale is your reference. Does this make any sense?
gthomas