I can highly recommend this meter. I have had many years of great service. When I stupidly destroyed one, I got another and have had many more years of faultless service. Never had to replace a probe. Remember, never test anything that's not room temperature, and probes last a very long time.
https://hannainst.com/hi98128-phep-ph-tester.html
This one doesn't look bad, but I guess my question is which probe works best with (room temperature) wort. If you read the description of this model it reads "Great for drinking water, aquariums, pools, & ponds", which I read as for use with mostly water. Wort contains a lot of material that plugs up probes and require a more robust probe.
It's pretty common to see probe failure, I just want to maintain accuracy and reliability. I was wondering if anyone can shed light on single junction or double junction probe reliability. From what I read so far, most of the probes people are using for measuring pH in brewing are not the best fit because of the harsh environment.
Maybe the Milwaukee probes just suck, I dunno.
Like I said, I've never had problems over hundreds of batches, and brewing is all I use it for. Popular model sold by LHBS, MoreBeer, and many others. I think the Hanna blurb is just addressing bigger markets. Mash and wort are hardly harsh environments. Guys at LHBS say it's used for wine and canning stuff like tomato sauce by buyers without problems, those just may require occasional cleaning of the electrode. They sell a cleaning solution I've never used, just take a quick reading and rinse it off right away. Instructions don't specify regular cleaning, and they say calibrate monthly, but I find that's overkill. Again, the biggest cause of electrode failure for homebrewers is taking readings at high temperature, which gives an incorrectable wrong reading anyway.
My guess is that what you describe is is not the norm. Not saying it isn't true, but my experience with pH meters and other test equipment indicates to me that probe failure is not uncommon. My question was to see if someone on this forum were familiar with issue and why it happened, and the best method to prevent this from happening prematurely. The average life span of a pH probe is any where from 6 months to 2 years depending on the type of probe. This is pretty well documented.
Wort/beer is consider a harsh environment because it contains proteins which clog the permeable membrane on the glass bulb. When this is clog the hydrogen ions are blocked and the meter can't measure the electrical potential between the measured wort (in this case) and the reference solution contained within the probe. Basically, a pH meter is a form of a voltmeter.
I may have answered my own question doing research elsewhere on the web.
1. Dual junction probes are intended to work in a less than ideal environment and are more resistant to the clogging of the membrane. (Maybe)
2. A cleaning solution containing the enzyme pepsin should be used after every use (or brew) to remove any protein that may have collected on the bulb. Rinsing the probe in distilled water is not an effective cleaning method for proteins.
Hanna recommends cleaning regularly with a pepsin solution:
"The HI7073L is a special enzymatic cleaning solution that is specially formulated for use in applications were a pH electrode can be coated with proteins. Electrodes can become dirty from use and will produce inaccurate results even as they read correctly in a pH buffer. Hanna’s cleaning solutions eliminate impurities and residues that are left on electrode surfaces when immersed in samples during measurement and stored incorrectly. Hanna suggests cleaning the bulb and junction of your electrode on a regular basis to ensure that the probe is always clean and prevent any clogging of the junction."The cleaning solution is fairly cheap ($15.00 for 500mL) and should last a long time.
I don't know if anyone was interested in this, but I found it helpful.
Topic: pH probe failing too often (Read 3300 times)
