Ph meter help

[johnnycordner]

Hi, can you help me understand calibrating ph meters. I have a Dr Meter 838 ph meter. To calibrate it says to use distilled water to mix the calibration powder solutions. I read that ph meters require ions to give an accurate reading and that de-ionised water will prevent the pH meter from working properly. Also, that de-ionised water leeches the ions from the electrode in the pH meter rendering it useless. However, my confusion arises when I go to buy distilled water for mixing the calibration solutions they say that distillation process also removes the ions from the destilled water, like with de-ionsed water.
So is it ok to use this distilled water?
Does the powder put ions back in the distilled water?
Also, can I just use purified and boiled tap water?

 

[McMullan]

DI water is fine (pure enough) for making pH buffer. Yes, the powder buffer adds ions. The life of a pH probe is extended by using KCl storage buffer. You can make DI or distilled water at home, but you'll need specific equipment to pull it off. It's not simply a case of boiling water.

 

[johnnycordner]

DI water is fine (pure enough) for making pH buffer. Yes, the powder buffer adds ions. The life of a pH probe is extended by using KCl storage buffer. You can make DI or distilled water at home, but you'll need specific equipment to pull it off. It's not simply a case of boiling water.

Thanks.

 

[McMullan]

Forgot to note for use just for a pH meter/pen you won't need that much so it's best to buy DI water locally, somewhere like an aquarium shop or car parts (battery top-up water). A 5L/1.3Gal bottle of DI lasts me months to over over year. It's cheap to buy. And don't get hung up on odd pH readings in pure water. With fewer ions, the the purer the water gets, the probe won't really do its thing properly and gets a bit confused. Just remember the DI water is for prepping the buffers and washing the probe between readings.

 

[rushpapers]

Buy some Milwaukee 7.01 buffer solution.