The physicochemical quality reproduced by the standard is the value of molecular activity of hydrogen ions expressed by its pH exponent.
The certified pH value is traceable to the N.I.S.T. and the national pH measurement standard.
The pH value of standards depends on temperature and the values are shown in the certificate of the standard example.
pH standards examples are distributed in 100 cm3 bottles and 250 cm3 bottles.
pH standards evaluate the pH scale and they are designed for the standardisation of pH-meters and to check the accuracy of pH-electrodes.
pH STANDARDS LIST
LP | Type No. | Standard name | pH Value | Expanded Uncertainty (k=2) |
1. | BLS 099.010 | TETRO-XALATE | 1,68 | 0,01 |
2. | BLS 099.030 | CITRATE | 3,78 | 0,01 |
3. | BLS 099.040 | PHTHALATE | 4,01 | 0,01 |
4. | BLS 099.060 | PHOSPHATE | 6,86 | 0,01 |
5. | BLS 099.070 | PHOSPHATE | 7,00 | 0,01 |
6. | BLS 099.071 | PHOSPHATE | 7,41 | 0,01 |
7. | BLS 099.090 | BORATE | 9,18 | 0,02 |
8. | BLS 099.100 | CARBONATE | 10,01 | 0,02 |
9. | BLS 099.120 | CALCIUMATE | 12,4 | 0,1 |
The CRM pH certificate is issued as a reference material certificate confirming its metrological properties including PCA accreditation symbols, that confirm compliance with the requirements of ISO 17034 for manufacturers of reference materials.
For pH reference materials, a reference material certificate for compliance with ISO 17025 can be issued, which shows metrological properties with PCA accreditation symbols based on the signatory status of multilateral EA-MLA and ILAC-MRA agreements on mutual recognition of calibration certificates.
