My coworker is using an ORP electrode to measure the same solutions as I, but our readings are not e
No. Because ORP is a relative measurement, it is almost impossible to compare two ORP electrodes directly. ORP electrodes come equipped with bands made up of platinum, or gold, for example. Each band type will give you a different reading in the same solution. Even if the electrodes are of the same band type, the leak rate through the reference junction will affect your readings.