The meters that you stick into the soil are pretty much less than useless.
Get a decent pH meter or pen and measure the runoff water.
xxx.eseasongear.com or eseasongear on eBay has the best prices and a very wide selection of all makes and models.
I have the Milwaukee SM-101 and love it. ~$76 for the meter, but with all the solutions + shipping, came to ~$115. Yes, you will need the solutions no matter what meter you get.
DD