Pipette to draws in or eject liq. by electrical heating of gas in enclosed space

摘要

A pipette system used in automatic analysis consists of a temp.-controlled gas-filled hollow chamber of constant volume linked by means of a gas pipe to a receptacle from which it takes up liq. The take-up or ejection of liq. is driven by a controlled change of temp. in the gas filled chamber (3) which holds a peltier temp. sensor. The chamber (3) is an electrically-heated metal capillary tube through which the liq. is drawn or ejected. The temp. is measured by the temp.-dependent change in voltage during the constant application of electrical current-driven heat impulses.