A scientific calculator has two 'log' buttons on it. These are marked log and ln. The log key is used for calculations of the form \({\log _{10}}x\). For example, to work out that \(\log 10000 = 4 ...

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 ...