Coolants are best operated in a pH range of 8-10, and you can verify the range of your blend by checking its product data sheet. Under normal circumstances, the pH of your solution will not increase, yet it can fall dramatically when it is not properly maintained. Even a drop of 1 pH is detrimental because it indicates an abundance of bacteria.
Given the fact that coolants operate in a tight pH range, you will need to measure between each point. We recommend something with at least an accuracy of ±.2 pH so you will be able to correct the imbalance before it’s too late. The digital testers offers greater accuracy and a wider pH range, but require calibration using a calibration solution.