ORP Sensors – Are They Really The Best Thing "Since Sliced Bread"?

By Vadim Malkov, PhD, Hach

There have been many publications lately that claim universal appeal of the ORP sensors and their applicability across the board. This concerns me, because the authors sometimes forget to mention some well-known practical limitations of the method, let alone the realities of water treatment applications potentially influencing the sensor performance. This is why I’d like to set the record straight and provide a balanced account of what the ORP method and sensors are good for and where may be not be appropriate. I am doing this only because the misunderstanding of this method may cause confusion among the engineering companies specifying analytical equipment for water utilities and this, in turn, causes potential misapplication of this technology and failed end-user expectations.