pH Buffer Calibration Solution Kit 3-Pack: pH 4.00, pH 7.00, pH 10.00 Buffers — 250 ml (8.4 fl oz) Each — Color Coded — NIST Traceable for All pH Meters

Great value and a nice size that won't expire before I use it all. Solutions were accurate and came with certificates. pH 10 buffer read 0.02 higher than indicated on paperwork, but the 10 buffer is the hardest to keep stable and needs to stay fresh, so that's not bad. Other pH 10 buffers I have received have been off by as much as 0.45.These will be my go-to pH buffers if the price remains this reasonable.

As described

I am a chemist working in my own small lab. I like the size of standard solutions, very well packed with certificate of analysis for each standard. I do not use much of the standard so I am expected to have them until expired. However, I hope this product is available in case I need to buy them again. I highly recommend this product for calibration or standardization of pH meter.

I am really pleased with this company's products. I calibrated a pH meter to the 7.0 standard and then testing using Biopharm's 4.0 and 10.0 standard i obtained 3.94 and 10.10. The meter is only accurate +/- 0.1 pH so these standards are WELL within the accuracy of the meter. In addition the 3 buffers were efficiently packed in a box that can be reused for storage. The standards are also packed in a narrow neck bottle with a tight lid. (Minimising evaporation and CO2 absorbtion from the atmosphere.) The buffers were packed in order 4, 7, 10 from left to right and the NIST trace sheets were also in order front to back. I mention this because it shows the company pays very strict attention to details and order. That is exactly what i want from a quantitative chem lab producing standard solutions. From now on i am purchasing all my standard solutions from these people. THANKS!

Good product

I had to keep calibration consistent and the first set of your liquid was right on from the first time I used it and to the last few drops

Will buy again I bought them to calibrate my PH meter . Great product and very accurate.

We've got this solution before and it worked OK as far as we know no problems with electrode calibration, it's cheap.However this last batch I got, our pH meter kept giving electrode error.We borrowed buffer from a different lab and pH meter calibrated without a problem.I went back to check Biopharm buffers on calibrated pH meter.pH 4 = 3.95 LOT BB8872pH 7 = 7.13 LOT C2321EpH 10 = 9.84 LOT C0221DThis is way outside of advertised pH range.Will have to go with Fisher reagents next time.