what solution do you use to calibrate your pH meter?

[twd000]

recently had a problem with a drifting pH meter, and checked my 4 oz. bottles of calibration solution, only to realize they're expired by several years

Seems an expensive waste to buy the full bottles and have them go bad, or untrustworthy, before you can use them up

I see some other alternatives like a small 20 mL one-time-use sachet: Milwaukee M10007B pH 7.01 Calibration Solution Sachets (25)

Also I see some powder packets that you mix with distilled water: 20 Pack pH Buffer Solution Powder For Precise Calibration of pH Meter 761344867307 | eBay

But these are 6.86 instead of 7.01 that my meter needs

Doesn't distilled water drift after opening, by absorbing CO2?

Meter is a Milwaukee MW102

 

[VikeMan]

I see some other alternatives like a small 20 mL one-time-use sachet: Milwaukee M10007B pH 7.01 Calibration Solution Sachets (25)

Also I see some powder packets that you mix with distilled water: 20 Pack pH Buffer Solution Powder For Precise Calibration of pH Meter 761344867307 | eBay

There are 7.01 buffer sachets.
https://www.amazon.com/Milwaukee-M10007B-Packet-Buffer-Solution/dp/B007IT4EGC/

 

[twd000]

looks like there is a 5-year expiration date on the sachets. Sounds like 1x a month is the standard recommendation for calibrating? Basically works out to $1 per calibration

I'm re-reading the user manual for my meter - the probe is warrantied for only 6 months, and I'm seeing recommendations to buy a new probe every 12-18 months. Are you guys buying a new probe every year?

 

[marc1]

looks like there is a 5-year expiration date on the sachets. Sounds like 1x a month is the standard recommendation for calibrating? Basically works out to $1 per calibration

I'm re-reading the user manual for my meter - the probe is warrantied for only 6 months, and I'm seeing recommendations to buy a new probe every 12-18 months. Are you guys buying a new probe every year?

The consensus around here seems to be to calibrate before every usage session.

 

[VikeMan]

I'm re-reading the user manual for my meter - the probe is warrantied for only 6 months, and I'm seeing recommendations to buy a new probe every 12-18 months. Are you guys buying a new probe every year?

More like a couple of years, in my experience. Be sure to take good care of the probe. Don't use in hot wort, clean the probe now and then, and always store it in storage solution when not in use.

 

[ITV]

recently had a problem with a drifting pH meter, and checked my 4 oz. bottles of calibration solution, only to realize they're expired by several years

Seems an expensive waste to buy the full bottles and have them go bad, or untrustworthy, before you can use them up

I see some other alternatives like a small 20 mL one-time-use sachet: Milwaukee M10007B pH 7.01 Calibration Solution Sachets (25)

Also I see some powder packets that you mix with distilled water: 20 Pack pH Buffer Solution Powder For Precise Calibration of pH Meter 761344867307 | eBay

But these are 6.86 instead of 7.01 that my meter needs

Doesn't distilled water drift after opening, by absorbing CO2?

Meter is a Milwaukee MW102

I have the same meter and was having calibration issues. I ended up soaking my probe in the cleaning solution which solved my problem.