Need help with HACH ph meter

[LoneStarLori]

My hubs brought me a HACH 135 Minilab ph tester. I have tried, and tried to make this work. The instructions are pretty vague and I am really clueless in acid testing.
If anyone has used this, can you please explain the step by step. I can sometimes get a good calibration according to the pictures, but when I try to test a Eclipse Sonoma Dry Creek Chardonnay, I think I am getting 14.0 that seems really high. I was using the yellow liquid to calibrate.

Update, I did a test also using the vinters best acid testing kit and had to use 14 drop of the sodium hydroxide solution to get a stable rose color. I guess that would also be 14? Box says a white should be .75.

Help!

notice # 3 only says "measurement". well to me, the pictorial is really not user friendly for a first timer.

 

[ibglowin]

What is your sample size?
What is the strength of your NaOH
How much did you end up adding to get to the endpoint (in mL)?

Also you do not need the indicator if you use the pH meter. The endpoint is at pH=8.2

 

[LoneStarLori]

Using the vinters best kit, the sample was 15ML and the solution for the sodium hydroxide is .2N. which I had to add 14ML to get a stable rose color.

if I'm reading the directions right, if I had to add 14ML to get the result, the reading would be 14. Am I doing it wrong?

 

[ibglowin]

Using that sample size and that strength of NaOH the formula works out to "one to one" So for example if you added 7ml of NaOH your TA is 7.0g/L or 0.7% however you want to look at it. In this case you would have 14 g/L which sounds like waaayyy to high and clearly wrong. I am betting you went way over on your addition of NaOH. Use the pH meter and retest and go slow when you get to pH ~6.0. Make sure to swirl the beaker with each addition. You should be able to add at least 5ml fairly quickly with out going over the endpoint.

 

[LoneStarLori]

Is it possible to have raised the acid that high by adding Super Kleer in addition to the provided Chitosan?
I did the standard clearing and each time I racked, I used the AIO so I don't think gas was an issue, but I won't rule it out since it didn't clear correctly. The chitosan didn't clear as well as It should have after 10 days, so I added Super kleer. It is now crystal clear.

Now as far as the PH meter goes, I can't figure out how to use/calibrate it. That's why I was hoping maybe someone who had one of these could walk me through step-by-step how to calibate. I would forego calibration and just turn it on and measure a sample. But it goes straight to calibration mode when I turn it on. The button functions for calibration don't seem to match the instructions. The instructions are not written for a non-chemistry person.

I do appreciate your help, but if you could come show me, that would be really nice. I'll take you bay fishing

 

[LoneStarLori]

Just to check my methods, I did a sample of a IM Merlot ho ho im am stabilizing today. BEFORE I added Chitosan, I got a .7, that looks about right. Then I added the chitosan and measured again and got 6.5. So... I guess I am doing it right and the clearing agents should not have affected it.

 

[ibglowin]

No, the fining agents won't increase acid (or decrese for that matter.)

Meter looks easy enough Turn it on, press and hold the cal1 button insert into your calibration buffer or looks like you can just drop a few drops on the tip. You should see the cal display flashing on the meter. When it stops flashing you can repeat steps 1-3 to do another buffer (pH 7). When done press the Cal 1 button again and you should now be in the read mode (if there is one) or be ready to move on to your first sample. The meter is smart enough to detect a buffer vs a sample so if there is no true "read" mode to switch to then you just go from buffer to rinse the tip and then to sample, be sure to dry the tip with a kleenex between rinsing (with distilled water). It is OK to place the tip in a beaker for your test.

 

[LoneStarLori]

Yep, did all that. I tested the merlot with the meter using your method and it came out to .7, pretty much on with the vinters best kit. I am packing up both samples along with the meter and will send it with hubs tomorrow so he can have his lab guys at the office test it to see if they get the same reading. They are way more experienced at using that particular meter than I am. If the readings are correct, I am going to have some wine repairing to do. I'll let you know what they come up with.

 

[ibglowin]

Just for grins, what does the meter show the pH is for the Eclipse Chardonnay? I made that kit and my pH was 3.4. Did you tweak this kit in any way? Make it to less than the full 6 gallons?

 

[LoneStarLori]

That's the one I'm talking about that is reading at 14. That's where I think it's so out of whack. I didn't wait for a change. Not one. With the exception of adding that extra bit of super Kleer. I normally don't even bother as a testing my kids, but I was trying to learn how to use this pH meter. I've got a bunch of Mustang grapes waiting to be made into wine but I'm scared of it.

 

[ibglowin]

OK but what is the pH of the wine?

 

[LoneStarLori]

That's the one I am getting a reading of 14 on and makes no sense. if it were, I should be able to clean my driveway with it.
Clearly I am doing something wrong.

 

[Treeman]

From the instructions, a reading of 14 is an error message indicates that you don't have enough sample touching the tip of the meter. Are you putting a drop on the end or immersing the end in a small amount of wine? I would suggest dunking rather than sprinkling :0)

You will probably get a better calibration if you use both the yellow(7) and pink (4) standards for wine pH and the yellow and blue(10) for TA measurements. It looks like from the instructions that you need to push a second button on the end to add a second calibration point. Just be sure to rinse the tip and dab dry with a paper towel between samples or standards.


Cheers!

 

[LoneStarLori]

I was dunking it. But you have enlightened me on calibrating. I didn't know I was supposed to use two of the solutions.That's part of the Big picture here, I can't really figure out how to calibrate it.