Question on pH meter storage...in water?

[curator]

I just purchased a Milwaukee pH meter. On the instructions, it says to "always keep the pH probe wet with water." Then in another place, it says "do not use distilled or deionized water for storage purposes." What does this mean. Do I need to leave the probe in jar of salt water when not in use?

Also, tt came with a foil envelope of pH 7.01 buffer solution for calibration. Is there any reason I can't place that solution in a glass or platic container with a lid, rather than trying to fold over the foil envelope each time?

Thanks,

John

 

[skriz]

the packet of cal solution is a one time use only packet.

I've always kept the meter wet with cal solution.

 

[curator]

Skriz,

Thanks for your response. Do you mean you purchased some extra calibration fliud and placed in in a container...in which you kept the probe "business end" submerged? It seems like there would be enough calibration fluid in the foil packet to use for this purpose.

Thanks,

John

 

[flyingarmy]

I have some extra 7.0 & 10.0 packets that you can have a set to calibrate your probe.

 

[skriz]

Curator;216640 wrote: Skriz,

Thanks for your response. Do you mean you purchased some extra calibration fliud and placed in in a container...in which you kept the probe "business end" submerged? It seems like there would be enough calibration fluid in the foil packet to use for this purpose.

Thanks,

John

yep.

 

[tdwyatt]

uh, actually.....

pH meters use saturated KCL solution inside their probes to make "the battery" that the probe becomes to be ion selective for pH (protons) and detect the pH. Ideally, you would want to store the probe tip, especially if it is long term storage, in saturated KCl solution held in some type of cap (the probes come with a vinyl plastic cap for this setup when new). So long as the probe is in KCl solution and kept wet, it will not become depleted of KCl. KCl depletion is why probes only last for 18 to 24 months within an acceptable range of good accuracy when used as continuous monitors of system pH. So long as it is wet, it will be fine as far as sho9rt-term pH detection of proton levels, but the clock is ticking towards the ultimate depletion of the KCL in the probe if it is plain water that is keeping it wet. Seawater, even ASW, will keep in good for about 18 to 24, some report even 36 months, so if you don't have access to KCl solution, then at least use clean ASW

Calcium probes by PinPoint use a calcium chloride solution for their storage, and will require that you specifically use the calcium storage solution between uses for the PinPoint calcium probes.


HTH

 

[skriz]

ok, I would do what Tom says!