Calibration of Glasswares

PROCEDURE :
	Calibration of glassware means to correct or adjust the graduation of glassware that measure  volume.
	Volumetric apparatus must be suitably designed to assure accuracy.
	The design, construction and the capacity of volumetric Glassware must be in accordance with those laid down by the Bureau of Indian standards.
	Volumetric and graduated glass apparatus are grouped as,
	Class ' A' Apparatus     - These are procured along with calibration certificate.                                                                    - On receipt calibrate the glassware before using.                                                                    - Use in work of the high Accuracy.
	Class ' B' Apparatus     -  On receipt, allot serial number to glassware  and then                                                                       calibrate it before  using.                                                                      - Use in routine Work.
	All volumetric apparatus are normally calibrated at 27°C.
	Pharmacopoeial assays involving volumetric measurements require the use of accurately calibrated glassware.
	The tolerance on capacity for volumetric flask, pipette and burettes is laid down in the relevant Indian standards.
Clean and dry the glasswares before carrying out calibration.
DENSITY OF WATER(C)  :
Find the weight of empty density bottle(P) in gram.
Fill the  distilled water up to mark.
Weigh the density bottle with the water in it(Q).
Find the weight of water by subtracting the  weight  of the empty density bottle (Q - P).
Use the weight and volume of the water to calculate density.
Density of  distilled water   =     Weight(in gram)
Volume(in ml)
Unit of density is gm/ml.
FOR VOLUMETRIC FLASKS :
Weigh clean dried Volumetric flask (A).
Fill distilled water up to the mark and weigh(B).
Find out actual weight of distilled water (B-A).
Volume(in ml)  of the flask =     Actual Weight of  distilled water(in gram)                                                                                                    C
Where, C is Density of distilled water at 270C.
Measure the volume one time for class 'A' and three times for class 'B' apparatus and then calculate average (V).
Find the tolerance by subtracting the specified Capacity   from observed Capacity (Volume) of flask.
It must be within I.P.  Standard tolerance Limit.
		VOLUMETRIC FLASKS-Tolerance as per I.P. Normal Capacity 5 10 25 50 100 250 500 1000 Tolerance, ± ml Class `A' Class `B' 0.02 0.04 0.02 0.04 0.03 0.06 0.04 0.08 0.06 0.15 0.1 0.2 0.15 0.3 0.2 0.8
FOR ONE MARK PIPETTES AND GRADUATED PIPETTES :
Weigh previously dried beaker (A).
Pipette out distilled water up to the mark and transfer to previously dried beaker and weigh(B).
Find out actual weight of distilled water (B-A).
Volume(in ml) of the pipette  =   Actual Weight of distilled water(in gram)                                                                                                                                C  Where, C is Density of distilled water at 270C.
Measure the volume one time for class 'A' and three times for class 'B' apparatus and then calculate average (V).
Find the tolerance by subtracting the specified Capacity   from observed Capacity (Volume)  of Pipette.
It must be within I.P. Standard tolerance Limit.
		ONE MARK PIPETTES-Tolerance as per I.P. Normal Capacity(ml) 1 2 5 10 20 25 50 100 Tolerance, ± ml Class `A' Class `B' 0.01 0.02 0.01 0.02 0.02 0.03 0.02 0.03 0.03 0.05 0.03 0.06 0.04 0.08 0.06 0.12     GRADUATED PIPETTES- Tolerance as per I.P. Normal Capacity(ml) 1 2 5 10 25 Subdivision, ml 0.01 0.02 0.05 0.10 0.20 Tolerance, ± ml Class `A' Class `B' 0.006 0.01 0.03 0.05 0.1 0.02 0.06 0.1 0.15
FOR BURETTES:
Fill the clean dried burette with distilled water up to zero mark (A).
Transfer distilled water completely in previously dried and weighed beaker and weigh(B).
Find out actual weight of  distilled water(B-A)
Volume(in ml)  of the burette  =     Weight of  distilled water(in gram)                                                                                              C              Where, C is Density of  distilled water at 270C.
Measure the volume one time for class 'A' and three times for class 'B' apparatus and then calculate average (V).
Find the tolerance by subtracting the specified Capacity   from observed Capacity (Volume) of Burette.
It must be within I.P.  Standard tolerance Limit.
		Normal Capacity(ml) 10 25 50 100 Subdivision,ml 0.05 0.05 0.10 0.10 Tolerance, ± ml Class `A' Class `B' 0.01 0.03 0.05 0.1 0.02 0.06 0.10 0.2  BURETTES- Tolerance as per I.P.
ASSIGN GLASSWARE IDENTIFICATION NUMBER
Affix the tag to glassware with ID number after calibration.
For all calibrated glassware assign ID number as below,
CAL/QC/X/Y-Z
Where,   CAL  - Calibration
QC  - Quality Control
X   - code for glassware as mentioned below,
VF   - for Volumetric Flask
P    - for one mark pipette
GP  - for Graduated pipette
BR  - for burette
Y - actual volume (in ml)
Z -  serial Number starting from 01
Write the remark in format for glassware calibration in case of breakage of glassware.
Replace the new glassware with same Identification Number in case of breakage.
Calibrate the glasswares yearly.
Maintain the record of calibration up to 5 years.