We use cookies to improve functionality and personalize your content. To ensure compliance with the latest e-Privacy directive, we kindly ask for your consent to set these cookies. Learn more.
Measurement and Results - Lowest uncertainties for NIST-traceable pH buffer
I want to know if you have pH solutions that are NIST traceable, and if so, can they be provided with expanded uncertainties smaller than 0.006 pH units. Is that possible?
| Responses | |
|---|---|
|
admin
Total posts: 529
|
It is not possible to provide a pH product with an expanded uncertainty (U) of 0.006 pH units if that product is certified via direct comparison to a NIST SRM, which is the approach used at Inorganic Ventures (i.e., NIST-traceable). The reason is that the NIST SRMs used in the certification process have expanded uncertainties of at least 0.010 pH units, and some NIST SRMs have even higher U. As a result, even if our certification process did not incorporate additional error budget terms such as measurement error or stability/homogeneity assessments (which are necessary for ISO Guide 34 products), it would not be possible to provide a product with an expanded uncertainty lower than that of the NIST SRM used for certification. |