anthony middleton

it is a simple device that i bought very cheap at a DIY store. i dont think it is battery operated , it just simply has two metal prongs which you stick in the ground and a meter which reads the ph. The two prongs are of different metals. They cause a 'Galvanic' action between them in the presence of moisture in the soil. The flow of electrons between them causes ionisation which gives the 'Conductivity' of the soil as a pH reading. http://www.fresh-environment.com air duct cleaning San Francisco air duct cleaning San Mateo