What/which measurement equipment is recommended?

[jgmann67]

Others join in as interest dictates, I guess.

The cover specifically said do not use distilled water for storage solution. So, I'll dig up some storage solution somewhere.

I'm going to test the theory on how these readout (round up or whatever) maybe. Craig has a better quality meter with a reading out to 2 decimal places. We'll see how the compare, maybe.

 

[Ajmassa]

I'm thinking no info given has been bad, otherwise someone woulda corrected me. I hope. My cheaper meter's instruction manual was a joke. I definitely trust that morewine guide over all.
And I can actually test that "rounding up" thing. Didn't think to do it till you brought it up. It's just a matter of getting out the powder mix and calibrating my 1st meter, which reads 2 decimal places in spite of being $15.
Also, I've been using the 4.01 buffer as storage without issues until a couple months ago when I finally ordered some actual storage solution.

 

[sour_grapes]

I do have a question: since this measures only to the tenth (00.0), does that mean that it rounds up/down, or must it cross a ph treshold before ticking up/down? For example: for an actual pH of 3.66, will it read 3.6 or 3.7?

I think you did not get any answers because we really couldn't guess. There are many schemes for doing analog-to-digital conversion. Here is a discussion for the main types:

https://en.wikipedia.org/wiki/Analog-to-digital_converter#Types

In my experience, most instruments (that I have encountered) use the successive approximation technique. That method would, if I am thinking about this correctly, do a "rounding," i.e., 3.64 would go to 3.6, and 3.66 would go to 3.7.

There is a lot more to consider, however. pH is a logarithmic scale. Does your sensor use a glass electrode, which mercifully has a linear response to this logarithmic scale? Or does it use a different sensor, with different response characteristics? Does your instrument perform the A-to-D conversion before or after accounting for the sensor response?

Obviously, we are not in a position to know these things. Your plan to try to find out experimentally is likely the best you can do!

 

[jgmann67]

In my experience, most instruments (that I have encountered) use the successive approximation technique. That method would, if I am thinking about this correctly, do a "rounding," i.e., 3.64 would go to 3.6, and 3.66 would go to 3.7.



Obviously, we are not in a position to know these things. Your plan to try to find out experimentally is likely the best you can do!

This is what I was thinking I'd find as well. Their way of getting "close enough for government work."