Haven't used that particular model, but yes they are functional. However, unless you have lots of tanks or a need to repetitively test your one tank, not much of a need for them.
I have the Milwaukee ph/temp tester. I have 5 tanks. I think it is a great device, but it takes a bit of getting used to. Much more accurate and easier to determine than the chemical method. You need to calibrate the meter every week or so.