Environmental Express® Oakton® One-Shot™ pH Buffer Solutions are supplied with NIST-traceable calibration reports stating accuracy at 25°C to ±0.010 pH, in addition to conversion values for pH/temperature—for the most accurate calibrations!

Certified Reference Materials (CRM) meet federal, state, and local requirements, providing standardized reference calibration for pH meters. Produced in compliance with ISO/IEC 17025:2017, ISO 17034:2016, ISO Guide 31, and ISO 33405, CRMs ensure top-tier accuracy, documentation, and standards. They undergo extensive stability, transportation, and repeatability testing, with uncertainty (U) assigned from these evaluations. Calibration reports are issued by an ISO 17034 and ISO 17025 accredited lab. Environmental Express® Oakton® monitors the solution over 1 to 2 years and informs users of any changes.