Smaller blades are set to the same pitch as the larger ones. Larger blades need more tension to get there. Smaller blades need less tension. My problem when I first used the tuner was that the tension adjustment was so coarse that it was easy to snap a small blade. I used the tuner to determine what a correctly tensioned #5 blade was set for and then backed the tension off, mounted a small blade, and used the tuner's meter to sneak up on the tension. It worked, and the blade did not break. The tension was between C & C#. Out of curiosity, I checked the blades mounted in my Pegas and EX21 saws today. The Pegas with a #2 blade was C#, and the EX21 with a #3 blade was a C#. The arms are set parallel with the table and I never adjust the tension.
I used a Korg TM-40 tuner with a meter so I could see what I was doing. Some tuners only have LEDs and might not work for this.