Hate to say it,but those are notorious for not being accurate-you should consider one of these as an alternative:
Not the best,but my plants have never complained-they're like $12 at the same place you got the meter from.
The one you ordered is a good moisture meter,but for ph,not so much..sorry for the bad news
**edit** I have one of those meters,that's how I know this to be true
The one you ordered is a good moisture meter,but for ph,not so much..sorry for the bad news
**edit** I have one of those meters,that's how I know this to be true