The pH value is one of the most important and therefore also one of the most frequently measured quantities in analytical chemistry. Sometimes, a simple pH test strip is sufficient for making a rapid check; precise pH meters are, however, required whenever accurate measuring results are needed. Such a pH meter is available in nearly every laboratory and is generally ready for use at a moment's notice. The measured pH value can be read off the pH meter directly and can also often be archived immediately in compliance with GLP.
However, to verify the accuracy of the measured value, the following points should always be considered before taking a pH measurement.