Chemical Forums

Chemistry Forums for Students => Analytical Chemistry Forum => Topic started by: pcm81 on July 28, 2019, 03:55:31 PM

Title: Calibrating 0.001 accuracy pH meter
Post by: pcm81 on July 28, 2019, 03:55:31 PM
I got a good deal on ebay on a tabe top pH meter.I used to use pH reference solutions (4, 7) from Amazon to calibrate my 0.01 handheld pH meter, but would like to switch to wider ranging set of standards that is most appropriate for Acumet XL50 meter. Would be nice to have a set that goes up to 12.
My question is: do i need to go with solutions or can i get good enough accuracy with buffer packs, which i dissolve in DI water? I find packs easier to store.
Can anyone recommend a line of reference solutions that does not cost an arm and a leg, yet offers solutions in wide pH range?
I don't "really" need the 3rd decimal point that my pH meter offers, but would like to have solid results from 2 decimal places for titration purposes, hence looking for ph reference line with multiple reference points for 2<pH<12 range.
Title: Re: Calibrating 0.001 accuracy pH meter
Post by: wildfyr on July 28, 2019, 09:30:46 PM
pH detectors are notoriously inaccurate and prone to drift. I don't even really trust is to two decimal places.

A conductivity meter is much more reliable.
Title: Re: Calibrating 0.001 accuracy pH meter
Post by: pcm81 on July 28, 2019, 10:14:00 PM
pH detectors are notoriously inaccurate and prone to drift. I don't even really trust is to two decimal places.
Hence the multi point calibration.

A conductivity meter is much more reliable.
This meter also has conductivity mode, but i haven't bought a real probe set yet. Experimenting with $15 pH probe from Amazon to make sure meter works ok.