Ricca’s VeriSpec® pH Buffer and Conductivity Standard Certified Reference Materials are ISO 17025/17034 accredited to provide the highest level of quality assurance. These products have undergone rigorous evaluations of manufacturing methods, quality control, stability, and homogeneity. As a result, a certificate with the specified property value, uncertainty, and traceability is available with every bottle. All three of our quality control laboratories are accredited to ISO/IEC 17025 for competence in laboratory testing and ISO 17034 for competence of reference material producers.