If you want to know the best way to get an accurate pH measurement, this shows the lab equipment needed and the processes used. When doing chemical reactions, sometimes the acidity or the basicity is important. This is usually defined as pH and measuring it can be very useful for getting the reaction right. There are a few ways to measure pH, and the simplest, cheapest, most reliable method is paper. But that's not all. See a whole lot of ways in this two-part video.
Watch this science video tutorial from Nurd Rage on how to measure pH levels with paper and meters with Dr. Lithium.
In the second video, go further to compensate for the non-idealities in a pH electrode.
Brought to you by one of WonderHowTo's favorite scientists, NurdRage.