Calibrating pH meter

[MrBJones]

Going to brew today, need to calibrate my new pH meter

1. Should the distilled water be warmed before mixing in the buffering powders?
2. Can the buffering solutions be reused? For how long, or how many times?
3. Once calibrated, how long - typically - until the meter needs to be calibrated again?

Thanks!

 

[ajdelange]

Going to brew today, need to calibrate my new pH meter
Should the distilled water be warmed before mixing in the buffering powders?

No

Can the buffering solutions be reused? For how long, or how many times?

Yes, for a couple of days. Mix new for each brew session

Once calibrated, how long - typically - until the meter needs to be calibrated again?

Before using your meter in a brewing session you should run the stability check on it described at https://www.homebrewtalk.com/showthread.php?t=302256

The broad answer is that some meters require recalibration every few minutes while some will hold a cal throughout an entire brew session. The object of the stability check is to find out which of these you have.

With modern meters of good design you will sometimes find that an electrode will hold its cal for weeks or even months but that same meter may drift off in a day. Do not rely on a single episode of exceptional stability. Recalibrate each brew day.

 

[MrBJones]

Will the solutions last longer if kept in small sealed containers?

 

[mabrungard]

Will the solutions last longer if kept in small sealed containers?

Yes. The prepared solution is the same as those you can buy in their liquid form. While the 4 and 7 solutions are relatively stable, the 10 solution is not. Since only the 4 and 7 solutions are used in a brewing setting, you can assume that the solutions will last about a year, which is about what the commercial solutions are stated to be good for.