Author Topic: pH Meters & Dairy - Measuring, Calibration, & Maintenance  (Read 3988 times)

Offline linuxboy

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Re: pH Meters & Dairy - Measuring, Calibration, & Maintenance
« Reply #30 on: February 08, 2012, 11:21:07 AM »
Not KCI, KCl. Potassium chloride.
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Offline Beans

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Re: pH Meters & Dairy - Measuring, Calibration, & Maintenance
« Reply #31 on: February 08, 2012, 12:11:14 PM »
Not KCI, KCl. Potassium chloride.

That makes more sense.  Thanks for the info.
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Offline Spoons

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Re: pH Meters & Dairy - Measuring, Calibration, & Maintenance
« Reply #32 on: November 10, 2013, 06:20:42 PM »
Yoav, if you're experiencing oddity, condition your meter, and if it still doesn't work, send it back.

To condition

- First remove oil. Do this by washing with regular detergent. Soapy water
- Second, remove protein. Do this either by soaking in 1% pepsin/rennin with HCl added (.1 M... about 2 pH) to activate it; or if you don't have pepsin/rennin, use those enzymatic contact lens cleaner solutions like Renu. They work just as well and are really cheap.
- Third, remove salts. Do this by soaking in an acid solution. Something like .1 HCl, or even vinegar, or citric acid.
- Fourth, unplug everything. Do this by soaking the end of the probe in hot, 80C saturated KCl solution (3-4 M concentration)

The big one is protein and KCl. If you do that and it's still wonky, not too much more you can do. except refill the reference solution, and/or replace the junction.


Revisiting an old thread  :o

Some of these instructions are clear, but I still need some reassurance.

Step 1: Remove oil
Clean in soapy water. Easy-peasy... but isn't the probe too sensitive? I have an Extech PH100. For some reason, I thought I had to avoid touching the tip of the probe. I need a bit of reassurance here...

Step 2 : Remove protein
I found this product ( http://www.walmart.com/ip/Renu-Daily-Protein-Remover-Liquid-1-Step-Tm-0.17-fl-oz/10533128 ), but the directions for cleaning contact lens says to just add a drop in an other lens cleaning solution. So do I just need to add a few drop in an ounce of distilled water? or do I need to get both solutions? How long do I soak? Also, what about this product? http://glengarrycheesemaking.on.ca/access.htm . Seems to me it takes care of steps 1 & 2 easily. Pretty cheap too!

Step 3 : Remove salts
Soak in vinegar. No prob.

Step 4 : Unplug everything
Is there a household product I can use for this? and how would I use it? (dilution rate, etc)


Final question : Would soaking the probe in Star San sanitizer do the job?
« Last Edit: November 10, 2013, 08:08:55 PM by Spoons »
- Eric

Offline linuxboy

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Re: pH Meters & Dairy - Measuring, Calibration, & Maintenance
« Reply #33 on: November 11, 2013, 06:05:07 AM »
Quote
isn't the probe too sensitive?
Kind of. It's sensitive to ion differentials. So if you store in deionized or distilled water, it will pull KCl (most probes) or whatever the solution is through. Otherwise, nah.

Quote
Seems to me it takes care of steps 1 & 2 easily. Pretty cheap too!
Yep, but remember this is for stubborn protein deposits. You can also use a bleach solution and a 10 min soak. oh and no, te renu liquid is not foil oil removal. that takes a degreaser.

Quote
Is there a household product I can use for this? and how would I use it? (dilution rate, etc)
Yes, salt replacer is KCl. But it's super cheap to buy online if you can't find. like $4/lb cheap. Make saturated solution. Not sure what more you need. Saturated solution is made when no more salt dissolves. Heat the water up so it's faster.  Or if you want calculate the molarity.

Or just buy commercial probe cleaner for $10 and soak in that for half a day. It usually does the job, although not quite as thorough as a full reconditioning process.

Also check the probe temp tolerances for the KCl soak. some should not go beyond 50-60C.
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Offline Spoons

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Re: pH Meters & Dairy - Measuring, Calibration, & Maintenance
« Reply #34 on: November 11, 2013, 07:35:32 AM »
Thanks, Mr. White!
- Eric


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