Gravimetric determination of pipette errors

In chemical measurements (for instance in titrimetric analysis) it is very important to precisely measure amount of liquid, the measurement is performed with use of various measuring vessels. Presently laboratories use all kinds of glass measuring vessels like: beakers, flasks, etc., for measurement of bigger volumes of liquid, and in case of small volumes glass pipettes. Glass pipettes have been used for very precise measurements since the 70’s of 20 century. In 1964 during XII Measuring Conference, a measuring value of a “liter” from outside SI set has been accepted for official use. A liter [l] officially stands for a cubic decimeter [dm3]. In analytical chemistry, it is much more convenient to express volume in liters, and such is used in various documents, norms and publications. Development of science results in development in metrology of various sizes. Today one can observe even more precise and accurate measuring instruments. It is not different in case of measuring liquids with use of pipettes, commonly known as „liquid handling”. Presently, laboratory operators use modern pipettes, which can dose volumes like tenth of microliter [ul].