Hach meter question

[bleak]

I haven’t seen much discussion about the Hach Pro+ pH meter lately. I’ve had mine for 4 years now, and although it has never been super reliable, lately it seems to be descending into the abyss. It takes an inordinate amount of time to stabilize, and I have to calibrate several times before it shows a consistent reading between the 4.01 and 7.01 solutions. Today I couldn’t get it to read consistently at all. The inconsistency isn’t huge as it shows about .05 lower than it should, but I’m not confident in its readings now.

I’m wondering if I should buy a new probe, which is rather costly, or just get a different one.

Also, my recent water report showed some big changes, which has me baffled. It seems that I'm chasing a moving target, and my pH readings consistently show 2 or so points above what Bru'nWater says they should be.

 

[ajdelange]

If you got 4 years of service out of a $125 meter you have done extremely well. You say it has never been 'super reliable'. What does that mean? If it was performing erratically when you first got it you should have had them replace it for you which they were doing readily in those early days as there were infant mortality problems with it (I even got a Hach rep to admit that to me) then.'

In any case it is now clearly showing normal signs of end of life and it needs to be replaced. I believe that the problems were all in the electrode (as one might expect and that's what the rep told me) so that ostensibly replacing the electrode should suffice. But were it my meter I think I'd go the extra $40 or $50 to get new electronics too as there are bound to have been some improvement in them as well (or at least in the firmware) over the last 4 years.

 

[bleak]

By "not super reliable" I mean that there has always been a bit of drift, and the stabilization time has always meant that calibration was more of an ordeal than I thought was necessary. I was one of those who had the first probe replaced after a short period of time, so I guess I got 3-1/2 years of service out of the meter. I'll go ahead and get a new probe, that will probably fix it up. Just wondering how others here have fared with their pH meters.

 

[day_trippr]

I somehow managed to destroy the bulb on my PP+, didn't discover it until checking the calibration on the next brew day two weeks later. But aside from that the meter had been working great for a couple of years, stability test and all.

Then the first replacement probe bought from Hach's Amazon store and "revived" with the recommended 60 minute soak in ph 7 solution displayed a nearly infinite response slope - it actually never hit any of the calibration targets no matter how long I let it sit - and would then display the dreaded "sensor?" error.

Thankfully the replacement of the replacement worked great - it's actually way faster than the original ever was - so I guess that's a plus. But be forewarned that there's no guarantee a replacement will work at all, which by extension indicates to me one could buy a brand new meter and still end up with a poopie sensor...

Cheers!

[edit] "poopie"? lol - that's not what I wrote

 

[bleak]

Instead of buying a new one, I hit my Hach with 10% hydrochloric acid for 5 minutes, and now it's performing better than it did when it was new. I only had to calibrate once, and afterward it went right to the pH of the solution and stayed there. I tested it again at the end of the brew day and it hit the numbers right away. I'm looking forward to another 4 years of service out of this thing.

 

[ajdelange]

Dunking an electrode with a broken bulb into HCl isn't going to fix it (the HCl has to stay inside the bulb). But it is good to know that HCl rejuvenates the Hach electrode. I doubt you'll get another 4 years (that you got 4 years already is, IMO, remarkable enough) but let's hope you do.