From what I have read and going by some of the more experienced scapers the Hannah meters seem to be highly regarded but then you're starting to get in the £100+ bracket. Something I've been considering for a while but I worry I'll start worrying about that .2 difference again
I've bought some of these for work. There is a potential problem with them, in that the storage solution for the pH electrode is a very "salty" 4 mol KCl ( mol KCl = 74.56 gl-1)solution.I was drooling at a 200 euro Hannah TDS/Ph pen combo pen the other day....
That looks OK.I bought a Voltcraft meter at £58 inc probe
I think I know which one you mean, I have my eye on the same one. Something I'll probably treat myself to one day when I'm feeling flush.I was drooling at a 200 euro Hannah TDS/Ph pen combo pen the other day....
That is it really, pH meters are quite high maintenance bits of kit. If people use them properly; two point calibration in pH7 and pH4, or pH10, buffers before every use and store the electrode in the correct molarity storage solution etc, they will get ~ accurate results, if they don't they won't.Interesting discussion, the issue with pH pens is maintaining the accuracy, the electrode needs to be kept wet in storage solution which is simply not di/RO water. I have a hanna combo pH/tds pen which was great to start and because I did not store it in the solution it now loses calibration within a week, need to replace the electrode at a cost of about £60.
The problem is that pH is a really strange measurement, it is both a log10 scale and a ratio. As you move towards pure water pH becomes less and less meaningful as a measurement.How accurate do we really need? I use ph4 & ph7 calibration fluid & calibrate only when I need to compare ph from an outside source that has been tested with a different meter.