By Ann Lenhardt & Erin Lenhardt
The most common and economical method used for pipette calibration is gravimetric analysis, defined as the quantitative determination of an analyte based on the mass of a solid. Many internationally known standards such as the ISO 8655 Part 6: Gravimetric Methods for the Determination of Measurement Error and the ASTM E-11154-89 Standard Specification for Piston or Plunger Operated Volumetric Apparatus are built upon the gravimetric method of calibration; accordingly, most accredited ISO 17025 calibration laboratories use this method.