From Sensorex

pH scaleOnline  Resource — On their website, Sensorex produces a very informative technical education page about pH, what it is, how it is scaled and measured & much more. It’s online at

The page begins:

“One of the most widely used water measurements, pH is a measure of acidity and alkalinity, or caustic and base, respectively, of a solution. It is expressed typically on a numeric scale of 0-14. A value of 7 represents neutrality. Lower numbers indicate increasing acidity and higher numbers increasing alkalinity. Each unit of change represents a tenfold change in acidity or alkalinity which corresponds to the negative logarithm of the hydrogen-ion concentration or hydrogen-ion activity.”

pH Calculator page

Their helpful online pH Calculator page enables one to to determine the pH of a solution using the concentration, weight, or volume method. It is at:

Sensorex is a manufacturer of optical and electrochemical water quality sensors and instrumentation, online at:

edited by GRP