I use a battery powered pH meter, manufactured by Hanna Instruments, pn HI-1270. This unit was bought in 2005, from Elemental Scientific, located in Appleton, Wisconsin. The price at the time was $34.50. If you go this route, be aware that you will need to calibrate the meter, using a standard solution, before it is used. Its not just the soil that needs to be tested. If you plan on using tap water to irrigate your blueberry shrubs, then the water will need to be tested, as well. I use 5% white vinegar, from the grocery store, to pre-treat our tap water, before using this water on our blueberry shrubs.