Volumetric analysis is a method of quantitative chemical analysis in which quantities are measured in terms of volumes, either of solutions or of gases, using apparatus such as the burette, the pipette (a calibrated tube, filled by suction, capable of delivering a known volume of liquid), and the volumetric (calibrated) flask. The chief technique of volumetric analysis is titration; also important is the measurement in a gas burette of the gas produced in a reaction, the weight of one reactant being known.