CALIBRATION OF VOLUMETRIC GLASSWARE
3.2 PROCEDURE FOR CALIBRATION OF VOLUMETRIC FLASKS:
3.2.1 Label the volumetric flasks with serial numbers or note down the number, which is present on flask.
3.2.2 Weigh the volumetric to be calibrated on a calibrated analytical balance and note down its weight (w1).
3.2.3 Fill the volumetric flask upto the mark with Distilled water (Which is adjusted to 25 degrees) and close the flask with the stopper immediately.
3.2.3 Weight the volumetric flask again (w2).Calculate the weight of water by deducting (w2- w1).
3.2.4 Measured weight of water is converted into volume by using the following factor: 1ml of water at 25 degrees is equivalent to 0.99602 grams i.e. 0.99602 grams of water is equivalent to 1 ml of water. Factor = 1/0.99602 = 1.004. Record the results in the calibration format and compare with the limits given in the acceptance criteria.
3.3 PROCEDURE FOR CALIBRATION OF PIPETTES:
3.3.1 Note down the serial numbers of the pipettes to be calibrated.
3.3.2 Weigh an empty clean dried stopper flask or weighing bottle and note down its weight (w1).
3.3.3 Fill the pipette with water up to the mark and adjust to the lower meniscus of the water.
3.3.4 The water drop adhering to the jet is removed by bringing the surface of water contained in a beaker to the jet of the pipette and remove without jerking.
3.3.5 Release the water into weighed beaker and note down its weight w2.
3.3.6 Held the pipette so that the jet of the pipette is in contact with the side of the wall, if necessary incline the pipette slightly.
3.3.7 Stopper the flask immediately and note down its weight (w2).
3.3.8 The weight of water is converted into measured volume by multiplying with the factor (1.004).
3.3.9 Record the results in the calibration format and compare the results with the limits given in the acceptance criteria.
3.4 PROCEDURE FOR CALIBRATION OF BURETTE:
3.4.1 Note down the serial number of the Burettes to be calibrated.
3.4.2 Weigh an empty, dried Beaker and note down its weight (w1).
3.4.3 Fill the Burette with the Purified water upto the mark, taking precautions that no air bubbles should present in the Burette.
3.4.4 Transfer the volume to be calibrated to weighed beaker and note down its weight (w2).
3.4.5 Calculate the measured water weight by deducting w1 from w2 (w2-w1).
3.4.6 The weight of water shall be converted into volume by multiplying with 1.004.
3.4.7 The accuracy of following volumes has to be checked for the burette 10ml, 25ml and 50ml.
3.4.8 Record the results in the calibration format and compare with the limits given in the acceptance criteria.
3.4.9 Before calibrating the Burette, it is essential to establish that the burette is satisfactory with regard to a) leakage b) delivery time.
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