I would not recommend this tester to anyone. Waste of money. Received item is faulty and cannot be calibrated. In solution PH9,18 it always shows random numbers. Seller keep saying you must calibrate, but can’t hear that it is an actual problem - wrong numbers during calibration. Such a disappointment.
Very bad item. Doesn’t work properly.
Not worth the double price. Basically just the TDs and pH, all the rest is useless. It's not really measure salinity, it's a function of the TDs.