Calibration Solutions/Buffers

[Isaac]

I tend to clean my probes monthly and calibrate at least quarterly... tiny packets at the LFS get expensive. Frankly 2-4oz bottles on amazon get expensive. Go to the source! I just picked up the following from fischer scientific:

Cat No.: R5889000500 Qty: 1 Unit: EA Price: $14.39 Line Total: $14.39
Description: KCL COND STD 50,000 uS/CM

vs $15 for 2oz on amazon... American Marine "PINPOINT" knowingly overprices it due to lack of other retail options available. Also no expiration date.

Cat No.: S25849 Qty: 1 Unit: EA Price: $6.85 Line Total: $6.85
Description: BUFFER SOL PH 10.00 500 ML BL

Cat No.: S25849B Qty: 1 Unit: EA Price: $6.85 Line Total: $6.85
Description: BUFFER SOL PH 7.00 500ML YLW

Cat No.: S25849A Qty: 1 Unit: EA Price: $6.85 Line Total: $6.85
Description: BUFFER SOL PH 4.00 500ML RED

~$7.50 for 8oz bottle on amazon from Atlas Scientific. 4/7/10, 4/7, and 7/10 combo available as well.

500ml is slightly under 17oz. Easy math. Sure, if you are "prime" shipping is free, and fishersci is 8% shipping ($10 min) + $4 fuel surcharge, but in the end you have properly documented product, and enough of it that you dont cross contaminate.

This is the perfect thing to group buy in the future if there are enough OCD ppl like myself

[victoly]

Or you could work at an environmental consulting firm and throw away more cal solution in a day than a hobbyist would use in a year. That's option b

[FarmerTy]

I still just stick to the small packets for calibration for pH. pH 4.0 and pH 10.0 react to air very quickly and will cause your calibration fluid to drift off its setpoint. We used to throw the larger bottles away all the time when I was an environmental consultant because of this issue. Of course, we were also being audited for our field practices by the government so maybe we had to be just a little more picky about it.

[Isaac]

so, in other words, you are throwing them away into a bin to share with reefers... amiright?

[FarmerTy]

so, in other words, you are throwing them away into a bin to share with reefers... amiright?

Real estate agents and grad students don't carry much pH calibration fluids these days. [emoji14]

[Isaac]

so, in other words, you are throwing them away into a bin to share with reefers... amiright?

Real estate agents and grad students don't carry much pH calibration fluids these days. [emoji14]

bah, how would we know if its safe to eat off the counters then?