PH meter question

[silverwolf72]

Does 2 point calibration worth the extra money over the single point? I know it's more accurate but do I really need to be? I know a lot of people are always get the best you can but at a certain point you gotta start asking your self is it really necessary to be that accurate.

 

[chinaman4u]

I always thought you need two points. One for a 4.0 reference, and the other, 10.0 to adjust the slope of the ph line. Then your readings in between is accurate.