Just went out and tested the ph and fertility of my soil with my three pronged PH meter. Let me state right up front I have no confidence in this thing at all. My PH tested right at 7 and my soil fertility very low.
Now I could be wrong, but the reason I have no faith in these readings is because no matter where I stuck the thing I got almost identical readings (maybe just a fraction off in either direction).
After testing about half a dozen places in the bog I moved up the hill, seedling bed, vegetable bed, rose bed and still everywhere read the same. The bog was as usual very wet, as I moved up the hill naturally things got drier. I left the probes in the soil for over a minute each time, and cleaned the probes after each reading.