Russ- Send that thing back!! It is supposed to be with in 1/10th of a point when used correcty. I know you are a pretty knowledgabe guy so I assume you followed the instructions. I am pretty sure Biologic will exchange it if it's defective.

I have one as well and it has proven to be very accurate when used properly. If you just stick the wand in the ground and don't follow the directions it tends to be a little "off."

Overall, if you are looking to just test your PH this (biologic ph meter) is a decent option but you really can't do better then a soil sample. I am sure many on here will argree how important it is to know exactly what you are dealing with and what you need beyond just lime. TGK