[curiouscat]

Any tips on selecting a good pH meter for general lab use? There seems an overwhelmingly large variety & I'm a bit lost.  Any pitfalls?

e.g. http://www.coleparmer.com/Category/pH_Meters_Ion_Meters_and_ISFET_Meters/3415

I don't need high accuracy. 0.5 pH units or so ought to be OK for most things we do. Reliability, ease of use & robustness are more essential. Whether handheld or labtop unit doesn't matter.

[Arkcon]

Sounds like you want one of the many handheld models, given that you need ease of use, and you're willing to sacrifice resolution.  Just about any model of hand held one will work fine for a long time, so long as people don't abuse the instrument, and you check calibration daily with clean, NIST traceable standardization buffers.

[curiouscat]

Sounds like you want one of the many handheld models, given that you need ease of use, and you're willing to sacrifice resolution.  Just about any model of hand held one will work fine for a long time, so long as people don't abuse the instrument, and you check calibration daily with clean, NIST traceable standardization buffers.

Thank you!

Dumb question: Assuming the unit let's you check pH of 1 & 14 does that mean most units are fit for contact with corrosives acids / bases etc.?  Or must I look for special ones?

There's HCl / H2SO4 / H2O2 / NaOH in many of our samples. Nothing too exotic but still.

[Furanone]

I use an Aqualyser from Nico2000.net out of UK. The nice thing about this unit is it allows you to not only connect pH probe, but also dissolved oxygen, temperature, and three other ion specific electrodes of your choice (eg. sodium, potassium, calcium, nitrate, chloride, etc.), and it monitors and records all data over time (you set measuring time interval). Very useful for fermentations where you want to see the decrease in pH over time as the fermentation progresses. Fairly reasonably priced at around $1000-2000 USD depending on which probes you select.

[Arkcon]

Yes, the plastic body and the thin glass electrode can handle exposure to strong acids and alkali.  You won't actually get a reading of ph 1 to 14, unless you actually calibrate the electrode to those pH values, and its not easy to get a good slope with those buffers, if you can find them at all.

[Borek]

Glass electrodes survive acids much better than alkalies.

[curiouscat]

Thanks for those tips!