Several new permanent reference cells have emerged in recent years with the advantages of smaller size and apparent longer life. The present test program was developed to assess the relative service life provided by various permanent reference cell designs. The natural tendency for the potential of a Cu-CuSO4 reference cell to vary must also be considered. Some causes of this variation may be due to the age of the cell and differences in manufacturing. Four tests (CuSO4 leaching, chloride leaching, dry-out tendencies and "real-world" testing) were performed on six permanent reference cells (PRC) samples. This paper discusses the testing results and how these results can be useful for the development of a standardized test method.