Reagecon manufactures a range of pH Buffer Certified Reference Materials (CRMs), which are manufactured and certified in accordance with the requirements of ISO 17034.
Their ISO 17034 pH CRM range covers pH 1.697 to pH 12.00 inclusive.
All are manufactured to exacting specifications with an extended shelf life and stability, even after opening the bottle.
These pH Buffer CRMs are directly traceable to the IUPAC pH scale by an unbroken chain of traceability. This is achieved through a traceable series of comparisons, with the key reference materials being Standard Reference Materials (SRMs) manufactured by NIST.
Your pH measurements can only be as good as the pH Buffers that you use. If your pH calibration is made using traceable pH Buffers, then you have a direct link to the International pH scale for your measurements. Without this link, you are not entitled to report your measurements in pH units, so the number displayed on your pH meter is just that - a number and is not a pH value. The common link that is achieved by traceability allows comparability of results regardless of:
Traceable analysis necessary for consistency and universal acceptance of your pH results - including acceptance by regulatory bodies.