Calibration of burettes

Calibration of Burettes.—Burettes are most simply calibrated by the Ostwald method with the help of a small pipette (generally 2 C.C.), the volume of which has been accurately determined (Fig. 3). The calibration pipette is attached to the burette in the manner shown in the figure (Fig. 4). 

If the burette is furnished with a glass tap, the clip I is omitted. The pipette may be kept in position by means of a loop of copper wire passing round the burette and the upper end of the stem of the pipette. 

As with pipettes, so also in the case of burettes, attention must be paid to the rate at which the liquid is allowed to flow out. The minimum time of outflow advisable will depend on the volume of liquid delivered for 30 c.c. it should be not less than about 40 seconds. 

---