Test of electronic tuners

I use the tone generator in my Peterson V-SAM  to test the accuracy on some electronic tuners.

Most essential is the precision with which the tuner can display the result!  Even if the tuner can measure with high precision, it is not shure it is able to present the result with the same precision!

Tuners have an interval where they show that the note is in tune! I have measured how wide this interval is. If an interval is 6 cent wide, it means -3 cent below and +3 cent above the correct pitch. Quite often the approved interval is not centered at the correct pitch.

 
10 cent Cherub Guitar Mate
Precision not specified in the manual.
6 cent KORG DT-3
The manual says the precision is 1 cent.
6 cent Intellitouch
In the higher octaves the interval was centered about 2 cents sharp. The manual says the precision is "better than one cent".
6 cent Intelli IMT-900 Cromatic Tuner
The approved interval was 3-4 cent sharp.
4-5 cent KORG CA-30
The manual says the precision is 1 cent.
4 cent D'Addario Micro Tuner
The approved interval was 1 cent flat in higher octaves.