HOW TO SUCCESSFULLY MEASURE pH IN PURE WATER

摘要

pH is a difficult process parameter to measure. Solution chemistries can be ‘weird’, temperatures andrnpressures change, sensors get fouled and sometimes broken. Measuring pH can be miserable!rnHowever, strange as it may seem, many people have the most difficulty measuring pH in an processrnthat has temperature controlled to 25℃, is low pressure, and has a very simple, clean chemistry. Thernapplication is the measurement of clean water, specifically pure water. Whether it is in the lab or inrnthe process it is the most difficult pH measurement. Simply, the water is too clean. Any andrneverything seems to affect the measurement. All the criteria that are critical to success; from samplerncontamination, temperature and flow effects, grounding and streaming potentials, reference potentials,rncalibration and installation specifics, to sensor selection will be explored and explained.