The pH scale is a convenient way of measuring the hydrogen ion concentration. It is a logarithmic scale with a base of 10. This means that it goes up in factors of 10pH = -log10[H+]This is read as: minus log to the base 10 of the hydrogen ion concentration. If the hydrogen ion concentration is 0.1 or 10-1 then the pH is 1. If the hydrogen ion concentration is 0.01 or 10-2 then the pH is 2. If the hydrogen ion concentration is 0.001 or 10-3 then the pH is 3. For each increase of one pH unit, the hydrogen ion concentration decreases by a tenth or 1/10. The inverse is also true.[H+] = 10-pHIn practice, the pH scale runs from -1 to just over 14.