Nature Metal pH meter silverMeasuring is knowing! The pH meter makes it easy to measure the acidity of the soil. The outer scale of the pH meter is made of silver coloured ABS. The value meter is equipped with a mechanical scale. The scale goes from 3 to 10. From 3 to 7 means the soil is acidic, from 7 to 10 means the soil is alkaline. You put 3 4 of the stem in the ground. After about 1 minute, you can read the result.