For laboratories involved in a accreditation or certification program, the use of certified and accredited standard solutions traceable to their national standards is highly recommended.
Radiometer Analytical is part of the Hach Lange group and their Calibration Laboratory, located in Berlin, is accredited for the calibration of certified pH and conductivity standards by DKD, the German national accreditation authority. This accreditation (No. DKD-K-47901) is recognised in more than 35 countries.
All standards are formulated in compliance with NIST, IUPAC and DIN19266 specifications.

IUPAC Series certified pH standards are fully traceable to the Standard Hydrogen Electrode through
Certified Reference Material produced by the Primary Laboratory of either NIST or DFM.
Radiometer Analytical certified conductivity standards are fully traceable to SI units via Certified Reference Materials manufactured by NIST. They are prepared and calibrated according to the internationally recognised demal scale laid down by the International Organisation of Legal Metrology (OIML – Recommendation No. 56).
All of the certified standards solutions come in sealed containers guaranteeing pH or conductivity values for a full two or four years, and are delivered with a DKD Calibration Certificate and a Certificate of Conformity and Traceability drawn up according to ISO Guide 31.
Click here for more on Certified pH and Conductivity Standards Brochure
Click here for example Certification
For live pricing info please visit http://www.camlab.co.uk/radiometer-ph-buffers-p25392.aspx