Controlled, Economical and Reliable Volume Measurement System for the Laboratory

Volume measurements are the most common measurements in the analytical laboratory and hence often receive minimal attention. At the Savannah River Plant (SRP), major changes in pipeting techniques and equipment were made that have reduced equipment costs by over $1,000,000 since 1982 and have cut pipeting and radiation exposure time by at least 50%. Extensive statistical studies were made to assure that the quality of volumetric measurements was not compromised by the changes. The paper will discuss: the former program which used glass micropipets for accountability measurements and air displacement pipetors (ADP) with disposable tips for routine measurements; the experiments which revealed half the error associated with ADPs was due to equipment and half to operators; studies which provided information to reduce both types of error; a training program for pipet operators and a calibration program for adjustable ADPs; and the volumetric measurements control program which uses automated equipment and software to facilitate periodic calibration checks and/or recalibration of over 250 adjustable ADPs being used in one SRP laboratory.