borax calibration solution

[salty joe]

Would using a Borax solution of pH 9.81 be a good replacement for the pH 10 calibration solution? http://web.archive.org/web/20021015005420/www.animalnetwork.com/fish2/aqfm/2000/feb/bio/default.asp

At the least, I plan to use it to check my Pinpoint pH meter to see if it accurately reads 9.81. Would the Borax solution go bad if kept tightly sealed at room temp?

 

[bertoni]

I would use a pH 10 calibration solution. That borax solution is good for a sanity test, but it's not good enough for calibration, in my opinion.

 

[disc1]

Would using a Borax solution of pH 9.81 be a good replacement for the pH 10 calibration solution? http://web.archive.org/web/20021015005420/www.animalnetwork.com/fish2/aqfm/2000/feb/bio/default.asp

At the least, I plan to use it to check my Pinpoint pH meter to see if it accurately reads 9.81. Would the Borax solution go bad if kept tightly sealed at room temp?

That would leave your slope pretty far off unless your meter allows you to choose the actual cal points. Most don't. And of course you would need to do a temperature correction on the 9.81 number to use it as a calibrant.

I would stick with a pH 10 calibrator.

 

[salty joe]

Thanks guys. I'll just use it for the sanity test, HA!

If kept tightly closed, would the Borax solution stay good for a long while? Like a year maybe?

 

[bertoni]

I'm not sure. It probably would be okay for some period of time, although carbon dioxide might dissolve into it eventually.