The value of the OTO test is to tell whether you have chlorine in the pool on a quick daily check when there are no problems going on, not so much for an exact number.
If it's clear you have no clorine, break out the big kit and find out what's going on.
If it's pale yellow (below about 2 on the scale) your clorine is too low, break out the big kit and see what's going on.
If it's yellow you are good for another day until it's time to do your full weekly testing.
If it's dark yellow to orange to brown you are shocking your pool and the chlorine is still on the high side.
IF you are doing your full testing weekly this is really all the info you need on a daily basis
If it's yellow it's good
if it's paile yellow to clear it's low
If it's deep yellow to orange or brown it's too high to WAY to high.