In Reply to: Proof meter reads too high posted by Jerry on June 19, 2018 at 12:00:46:
If someone installed the NAA meter on an N, it will read 56% too high. Proofmeters are known for being short lived. Difficult to take apart & might not be able to re-calibrate if successful at opening it. Just above the hours counter, the words "Hours at 1580 RPM" appear on an 8N meter and "Hours at 1515 RPM" appear on NAA meter.