pH /piː ˈeɪtʃ/ BrE AmE ( also pˈH ˌvalue ) noun [singular]
[ Date: 1900-2000 ; Language: German ; Origin: potenz 'power' + H , sign for hydrogen ]
a number on a scale of 0 to 14 which shows how acid or ↑ alkaline a substance is ⇨ litmus test
pH of
soil with a pH of 3.1