Awhile ago there was a thread about the different levels of stimulation on a Tri tronics collar. I always thought it started at a low 1 then a medium 1, high 1, low 2 etc. I'd never really thought about it, and wondered about the thread.
Today I didn't think my collar was working right, so I dug out a test light that used to come with the collars, to check it.
If you have an old light, or they still sell them, get one. It was very enlightening. (no pun intended) I don't know what kind of meter could be used instead of a light, or how the test light's brightness translates to levels of stimulation to the dog, or how the pulses enter into it. But there sure is a big difference between a low, medium, and a high 3 looking at the test light.
With the test light a high 3 is brighter than a medium 4, and maybe brighter than a medium 5. I guess I was used to using a high 3, and wasn't pushing both buttons today to the point that I thought the collar wasn't working...I have a big band aid on my "button thumb".
If you hold the collar up to your ear you can even hear a big difference between the low and mediums and the high at any number level you select.