Formulated for use with POEs as well as mineral oils and alkylbenzene, Phase III is an inexpensive, disposable test kit that provides proof-positive that acid level in refrigeration oil is either safe or unsafe. Phase separation makes it easy to see change in color of acid indicator (even if a leak detection dye has been added to the oil). With just two bottles to use, it is simple, safe, accurate, and small enough that you can carry several in your tool box.