Here’s some information. However i have read forums where they have still been working after 2 year.
SEN0169( black) is for industry purpose which allows the probe could stay in solution for a long time, generally speaking, it could lasts for half a year or more, depending on the solutions, e.g. tempreture, pH, turbidity etc . You could clean the probe by clean water or better with KCL 5N solution when you find its reading is not stable or inaccurate.