Update on pH tester - Hanna Phep and pH Checker

[setsailsoon]

Folks,

I have color blindness in the red-purple shades so I have to use a pH meter to get reliable pH readings. I've used a Hanna Phep portable pH pen-style for over 18 months with great success. There are several brands similar to this unit that have good reviews but I haven't tried them. These units have a fixed life because the fluid in the glass probe is depleted each time it's used. I've used mine about 4 times per week and it finally stopped working... very suddenly. Just would not calibrate. So I tried the new thinner style with replaceable probe. Worked great for a couple weeks then stopped calibrating. Hanna tech support were superb and will send me out a new replaceable tip after I just send them an email with my order receipt as proof of purchase. I'll keep you posted on the progress. Support says this unit doesn't have a lot of returns, I just got a rare bad one. I think they've been fair with me on this and will keep you posted. I hope the replacement works well and I'll keep you posted.

Chris

 

[cowboycasey]

I am also colorblind but not in the red side, mine is on the green side... I can see camouflage miles away

 

[JoyfulNoise]

Storage conditions matter a lot. Some probe types need to be stored in a saturated potassium chloride solution, other use distilled water. It is always bad to let a pH probe tip go dry during storage and that will often ruin them or severely shorten their lifespans. Back in the good old days, our SCE pH probes could have their working solutions replaced by removing the tiny rubber stopper at the top of the probe to access the reference electrode solution. Top it off with a fresh load of calomel (mercury chloride), polish the glass tip, calibrate and you were good to go .... then everyone got all whiny about mercury being “poisonous” and switched over to the less stable silver chloride electrode .... bunch of whimps

 

[setsailsoon]

My Hanna Phep used their storage solution and they emphasized the "don't let it dry out" point that Matt made. I used storage solution about half the time and pool water the rest. It also dried out a couple of times, all of which I'm sure reduced the life a little. But the thing still lasted 18 months and I think that's pretty good for a pen style portable. The cheapo versions never lasted more than a month before they would not stabilize for calibration.

I'm looking forward to see how the checker works especially with the replaceable probe.

Chris

 

[JoyfulNoise]

Letting the bulb dry out is bad in multiple ways. Not to get into the detailed weeds of pH probes but it’s important to realize that the glass tip is not just simple glass. It’s actually an ion selective glass tri-layer consisting of a thin glass membrane doped with sodium ions and a thin layer of hydrated silica gel on either side. The glass membrane allows for exchange of sodium ions between the inner and outer surface (in response to the concentration of hydrogen ions in solution). If the hydrated silica layers dry out, then the sodium ion transfer is stopped and the probe may not come back to life.

I would say that tap water is far better to use than pool water but any water is better than no water at all.

 

[setsailsoon]

"Not to get into the detailed weeds of pH probes but it’s important to realize that the glass tip is not just simple glass. It’s actually an ion selective glass tri-layer consisting of a thin glass membrane doped with sodium ions and a thin layer of hydrated silica gel on either side. The glass membrane allows for exchange of sodium ions between the inner and outer surface (in response to the concentration of hydrogen ions in solution). If the hydrated silica layers dry out, then the sodium ion transfer is stopped and the probe may not come back to life."

I bet you didn't even Google and paste ... you never cease to amaze!