They might show up as slightly acidic or slightly alkaline because of this. The pH scale measures how strongly acidic or alkaline a solution is using a set of values from pH 0 to pH 14.

Soil pH or soil reaction is an indication of the acidity or alkalinity of soil and is measured in pH units. Soil pH is defined as the negative logarithm of the hydrogen ion concentration. The pH scale ...

pH electrodes are analytical sensors for measuring potential of hydrogen (pH), the negative logarithm of the hydrogen ion activity in solution. The pH value of a substance is directly related to the ...