Keep in mind that a pH meter just stuck in the soil may not work at all if there is not enough soil moisture. You may have to wet it with distilled water--or carry a bottle of rain water, or tap water. Its best to check and compare the soil on your own lawn--I am assuming that you already have a soil test for your own property.
Well, OK. Calibrate your meter with your favorite brand of beer. Quality breweries are very careful that their product has the proper degree of acidity. Problem is, you can't buy just one can--you need a six pack. This is one of the few times that your recreational re-hydration fluid is a business expense--tax deductable.