One thing you may want to check anytime before you use the meter is to make sure it is zeroed out. With it off you can adjust the needle to zero it with the screw in the middle at the bottom.
Another thing to be careful of is static charge on plastic face meters. Often you can run your finger gently around the face and see the needle "magically" move. Gently wipe with damp soft soapy towel or find an "antistatic" cloth. Used to get them for "records", remember them?
