Tips For Using Hanna pH Meter?
I've just gotten a new Hanna pH meter, the one designed to work with dough. I'd like to know practical tips for using it. For example:
- It comes with two packets of pH 4.01 calibration solution. Once one has been opened the instructions say it won't maintain its calibrated value over time. Should I just stick the probe right into the packet, then throw the rest away?
- If I calibrate the meter, then how should I remove the calibration solution before measuring dough?
- What is the best way to clean the probe after measuring dough?
- If I measure the pH of my starter, can I just put the storage cap with its storage solution on until I want to measure the pH again a few hours later?
And, of course, any other tips you have found while using the meter!
TomP
I don't have the Hanna pH meter (though I used to), but in general I would do as follows:
1) Calibration solutions: put the opened sachet contents in a small plastic or glass bottle for storage. Really you should only use the solution once - put just enough to cover the tip in a plastic container and discard after using.
Hanna solutions will work out expensive I buy dry powder buffers off Aliexpress and make them up with deionised water. Make sure you get ph4.0 and 7.0 (not 6.86).
2) I have a big plastic mug that I fill up with tap water. Dunk the probe in there after calibration, then gently dry the tip with paper towel, then measure your sample.
3) I rinse the probe under a slow running tap, then dry before storage. If there is dough debris on the probe, rinse then clean in warm soapy water. Rinse again.
4) For temporary storage, tap water will do; you can add a pinch of potassium chloride if your tap water is very soft.
5) For storage solution, a 50/50 mix of 3M KCl and pH 4 buffer works well.
Lance
Thanks, Lance!
After opening a pouch of calibration solution and pouring it into a small storage, do you think the jar would do better stored in the refrigerator?
The solution keeps well enough at ambient and it minimises temperature changes during the calibration process.
I'll second the advice that Lance provided and add that you might want to rinse with deionized water between calibration/sample/storage solutions. That just depends on the quality and properties of your tap water. If it's low mineral and neutral pH, then it should be fine. I have very hard water and would use DI water if I had a pH meter. We kept all our storage and pH standard solutions at room temperature and discarded at the expiration date.
I don't have a pH meter because I found working with them in a chem lab setting was a maintenance headache. The Hanna probe may be more robust, but we always seemed to be needing to buy new probes due to use in less than ideal test solutions and also because of improper practices (like leaving the probe in DI water all day, not cleaning properly after use, dried out electrolyte, etc.).
Good luck with your new toy!
Thanks! I always have distilled water, so that's what I'm planning to use instead of DI, that and the Hanna storage solution.
I wouldn't be surprised if after measuring a number of starters and dough, so that I get a feel for what happens, I may not end up using the probe all that much. But I want to get the picture first.