Good question.  Each ...

Good question. 

Each industry water treating may have their own set of parameters and onsite preference. I saw this first when doing heavy oil produced water treating, many engineer, operators asked what test kit to have and what test method to use... In many cases, doing it is not as easy as talking and reading in manual as industrial water changes as we either take it out of live flow or it change from time to time, good examples would be dissolved oxygen and ORP measurements.

I believe an "ideal" test kit would be able to test water sample quick and easy onsite thus to get "real time" data. Also it can do various parameters by switching probes...