Stability check Hach Pro+

I did my first stability check about 3 months ago. Based on my last post I redid it tonight. Here are my results, not sure if this is good or not. I did notice more variability this time especially with minor changes in temp of the sample. Time is counting down from 1 hour 30 minutes.
1:30 4.0 at 75.4 (I had just calibrated it)
1:27 3.99 at 74.8
1:23 3.97 at 74.7
1:20 3.97 at 75.2
1:11 4.01 at 75.6
1:07 4.00 at 75.2
:56 3.93 at 73.9
:50 4.00 at 75.7
:49 4.01 at 76.1
:37 4.03 at 75.7
:35 4.01 at 75.6
:32 4.01 at 75.2
:26 4.07 at 77.2
:20 4.12 at 77.7
:18 4.00 at 75.6
:13 3.98 at 75.4
:11 3.95 at 75.2
:9 3.95 at 75.0
0 3.90 at 74.3

Does this mean the meter is still functioning correctly or does it mean it is starting to have a problem? Thanks for your help in advance

You definitely have a problem there. All I can suggest at this point is that you fill the cap with buffer (4 or 7), store overnight, recal and recheck stability. If it isn't more like what you saw when you first got the meter then I think you should contact Hach and see what they have to say. It shouldn't go south like this after 3 mos.

Thanks for the reply AJ. I called Hach and they are sending me some cleaning solution for free. I will try that and go from there.

I just wanted to let you know I had a sort of similar problem yesterday. It had been a couple of months since I used it last. I couldn't get a reading at all but instead got the ----- display which means the probe needs to be cleaned. So, it was way out of wack. That was just the beginning of my frustrations though.

The temperature was also really unstable so I took the batteries out and put them back in a couple of times just to see if it did anything and on one of those times I accidentally put a battery in backwards. In about a minute I noticed the unit getting really hot and the face plate was bubbling out! It was toast. I was so mad at myself. I sent them an email telling them what happened and they said it was under a 6 month warranty and they would replace it!

I'm very happy with their customer service. I was probably just going to give up on ph meters if I had to buy a new one. From now on I'll keep some probe cleaner on hand and be extremely careful when replacing batteries.

Interesting and unfortunate (as far as the meter goes). I have also had great customer service so far. They sent me some free cleaner (which didn't fix the problem) and some free pillow buffers. I used the cleaner per the manual instructions but it didn't help. When I tried to recalibrate it read the 7.0 buffer as 4.93-5.02 and would never let me move on from there. They are now sending me a free replacement probe. I hope this works. Frustrating for sure but at least the customer service has been good.

Two guys with failures in less than 3 mos. doesn't bode well.

How are you folks storing your probe? I've got to believe that keeping the bulb submerged in an appropriate KCl storage solution helps. I'm approaching 2 years old for the probe on my meter and its only shifted slightly in the calibration settings and the response is still fast. I do suspend the probe in 0.1M KCl solution that I made with an expired bottle of 4 buffer solution.

Took a peek at this meter and I see they recommend conditioning it for first use. Manual states to use tap water. Could this be a possible source of issue?

Last time I got serious about getting a meter again I was looking at an investment nearly the same as the meter itself for buffers and storage solution. Am I off?

I have owned 3 meters and have learned immensely from them and with each new meter I learned more about using them but I am enjoying brewing sans meter thanks to bru'n water...

I have kept mine stored with storage solution from Hach. I called them twice when I first got it and they said you could store it dry but that it would last longer with the storage solution.

We will hope, that as is often the case, there are initial production run problems with this new meter. If not we'll have to relegate it to the pile of 'bitterness of poor quality remains long after the sweetness of low price is forgotten' cheapo meters.

FWIW, I also stored mine in storage solution based on monkeyman's info from Hach. I don't think I conditioned it with tap water before using it though. We'll just have to see what happens with the new one. I'll make sure and update either way in the future.

Quick update on the replacement meter from Hach. So far so good. I did the tap water conditioning that the manual mentions. I missed that last time.

Also, this time I didn't store the probe in storage solution. Before storage I've been letting it sit in a bit of tap water, then dumping the water and leaving just a few drops in the cap. I've had 3 brew sessions with it now, including today and have stored it like this.

Today, after I checked my mash sample, I checked my 4.01 buffer again and it was reading 4.03-4.04, sort of bouncing between the two numbers. A touch high, but it's possible that my calibration wasn't perfect and it's within the margin of error if I remember correctly. Either way, close enough and no wacky performance like from the last one before I did it in permanently with the battery reversal. Don't do that :smack:

Jsguitar, glad you meter is working well. Mine unfortunately is going screwy again. It worked great for the last 3-4 brew sessions then yesterday it started doing what it did at the beginning with the old sensor. I mixed up so fresh buffer to calibrate it and it read the 7.0 buffer and 4.56 or so and stayed there. I though maybe I screwed up somewhere so I prepared some fresh buffer solution (the first one was only 2 weeks old) but got the same readings in the 7.0 buffer. It also wouldn't shut off or change screens so I had to open the battery compartment to get it to shut off. I had some cleaning solution that they sent me last time and tried letting is soak in that for about 5 minutes but still no change in the readings. I let it sit overnight in the cleaning solution and tried it again. Now it is reading 0.00 but if I shake it up it briefly goes up to .26 or so then comes back down to 0.00 and still won't shut off unless you open the battery compartment. I called Hach and once again they were great. They are sending me a whole new unit. I really hope it isn't something stupid that I am doing but i feel like I am following the manual.

anyone still using these with success a year later?

Yeah, mine is still working great. I just used it this last weekend with no issues.

corypedia said:

anyone still using these with success a year later?

Click to expand...

Yep, mine is great.

I posted the following under the pH meter calibration section.
Thought I would post this to help anyone thinking about pH meters. I bought the Hach Pro+ Christmas before last. I had problems with the first one that I posted here https://www.homebrewtalk.com/showthread.php?t=464632 but the company itself was very helpful. They sent me free buffers, cleaners, a new sensor and finally a whole new unit. I have used it about 15 times this past year and decided to run a stability check on it today for 75 minutes with fresh buffers. The temperature ranged from 74.7 to 75.4 and the meter initially read 4.01 in the 4.01 buffer for about 15 minutes then for the next 60 minutes it read a constant 4.02. I'm thinking that is pretty good. Hoping to get another year or more out of the sensor.
Also, just for fun, I rechecked the 4.01 buffer today which is about 22 hours later. Same buffer I mixed up yesterday and it read 4.00 at 75.2 F.