Another stupid ph question

[Antbeer]

So...another pH related question. How long does it, or should it take for you to get an accurate reading?

I've recently thrown away my pH meter in frustration because it was inconsistent with how long it took regardless of the various temperatures I attempted readings at.

This most recent experience gave me a different reading immediately after calibration, even after replacing with a brand new probe. (Kegland pH meter for reference). As in, I replaced the probe, calibrated in 4 solution, rinsed it off with RO water, then turned it off. Turned it back on, placed it back into a small sample of fresh 4 solution and it settled at 4.8 after a minute or so.

I also had trouble with the ph meter inconsistency. I’ve changed to ph paper which measures between 4.6 and 6.2.
Easy to take readings but not as clear as a clean number on a display. Would like to learn more about calibration of ph meters..

 

[jerrylotto]

Would like to learn more about calibration of ph meters..

I typically do a two-point calibration at pH 4 and 7 standards.

 

[Antbeer]

I typically do a two-point calibration at pH 4 and 7 standards.

Thanks
Do you keep the calibration button down until the display flashes or until the reset calibration value is steady?
I’ve got one of these ph meters

 

[mashdar]

My pH meter typically takes 3-8 seconds, if I had to guess. I think it's a Milwaukee "ph55 pro" - it was what the LHBS had on the shelf.
https://milwaukeeinstruments.com/mi...emperature-tester-with-atc-replaceable-probe/

I've had it a few years now, and whenever I calibrate it, it's pretty much still calibrated with the original tip. I store it in a buffer in the rubber tip. I replace the buffer every 3-6mo.

 

[jerrylotto]

Thanks
Do you keep the calibration button down until the display flashes or until the reset calibration value is steady?

I know nothing of calibration buttons or flashes of displays.

 

[B-Rad13]

I bought a meter from hydroponics shop and haven't had an issue since. I used to have problems like every one else until this one. Works like a champ I think it was under 50 bucks

 

[Antbeer]

My pH meter typically takes 3-8 seconds, if I had to guess. I think it's a Milwaukee "ph55 pro" - it was what the LHBS had on the shelf.
https://milwaukeeinstruments.com/mi...emperature-tester-with-atc-replaceable-probe/

I've had it a few years now, and whenever I calibrate it, it's pretty much still calibrated with the original tip. I store it in a buffer in the rubber tip. I replace the buffer every 3-6mo.

Thank you.
That is a helpful video on YouTube

 

[Antbeer]

I bought a meter from hydroponics shop and haven't had an issue since. I used to have problems like every one else until this one. Works like a champ I think it was under 50 bucks

Thank you

 

[Bassman2003]

So...another pH related question. How long does it, or should it take for you to get an accurate reading?

I've recently thrown away my pH meter in frustration because it was inconsistent with how long it took regardless of the various temperatures I attempted readings at.

This most recent experience gave me a different reading immediately after calibration, even after replacing with a brand new probe. (Kegland pH meter for reference). As in, I replaced the probe, calibrated in 4 solution, rinsed it off with RO water, then turned it off. Turned it back on, placed it back into a small sample of fresh 4 solution and it settled at 4.8 after a minute or so.

Sounds like the meter was not functioning correctly. These instruments can be fickle. Keep the probes wet in storage solution and only calibrate with 'in spec' calibration solution. If a reading takes more than a little while to stabilize the probe is probably wearing out or dirty.

 

[Knightshade]

How do you store your probes? If you let them dry out or store them in plain water, it's going to affect their accuracy over time. There are probe stabilizing solutions meant for storage. The probes for my Apera meter have slip-on covers that I fill with 4M KCl stabilizing solution and I've never had a problem.

Yep..it was sitting in a storage solution.