Calibration of Glassware

 1.0 OBJECTIVE

To lay down the procedure for Calibration of Glassware.

2.0 SCOPE

This SOP is applicable for calibration of glassware that is to be used in XXXX company

3.0 BACKGROUND

NIL

4.0 RESPONSIBILITY

4.1 All Analytical research personnel to follow the SOP.

4.2 Group leader of Analytical research to ensure the procedures to be followed.

4.3 Head Analytical research or his designee to ensure overall compliance.

5.0 PROCEDURE

5.1 Class “A” and class “B” grade volumetric flasks, pipettes, burettes and measuring cylinders shall be indented for the laboratory use.  

5.2 If  class “A”  glassware received with calibration certificate, then calibration is  not required.

5.3 If class “A” glassware received without calibration certificate, one unit shall be taken for calibration, for every twenty units.  

5.4 In case of class “B” glassware, calibration shall be done on all units.

5.5 All calibrated glassware shall be embossed as ‘C’ with glass marker.

5.6 Uncalibrated glassware shall not be used for analysis, all the uncalibrated glassware shall be kept under lock and key .

5.7 Clean and dry the glassware before calibration. Allow the glassware to attain the room temperature (25 ± 1°C) before calibration.

5.7.1 Calibration of glassware shall be done yearly once.

5.8 Calibration of volumetric flasks Following procedure is applicable for calibration volumetric flasks.

5.8.1 Weigh the previously washed and dried volumetric flask on calibrated balance, note   down the weight (W1) and record the details in “Calibration record of volumetric glassware” (Annexure-1).

5.8.2 Fill the volumetric flask upto the mark with water and keep for 1 hr at room  temperature, then weigh the flask (W2) and record the details in Annexure-1.

5.8.3 Determine the weight of water (W) and record the details in Annexure-1. Weight of water (W) = (W2 – W1)

5.8.4 Calculate the actual volume of water from weight of the water at 25°C, calculate %Error, and record the details in ‘’Calibration record of volumetric glassware’’(Refer Annexure 1).   

Calculation:

Actual volume of water (mL) = (W x Z)

where W is weight of water

Obtain the value of Z at 760mm Hg pressure at 25°C from official pharmacopoeia.

                  Actual capacity of volumetric flask in (mL) – Actual volume of water in (mL)

% Error  =  ----------------------------------------------------------------------------------------      x  100

                     Actual capacity of volumetric flask in (mL)

5.8.5 Acceptance criteria

Refer Annexure-2 for “ Acceptance criteria’s of volumetric glassware”.

5.9 Calibration of pipettes ( bulb / graduated )Following procedure is applicable for calibration of all capacity of pipettes.

5.9.1 Record the weight of previously cleaned and dried empty beaker (W1) and enter the details in “Calibration record of volumetric glassware” (bulb/graduated) (Annexure  - 1).

5.9.2 Pipette out the water up to the mark indicated.

5.9.3 Deliver the volume into the beaker, then weigh the beaker (W2) and record the details in Annexure-1.

5.9.4 Determine the weight of water (W) and record the details in Annexure-1.

Weight of water (W) = (W2 – W1).

5.9.5 Calculations:

Calculate the actual volume of water, % Error as mentioned in point No.5.8.4 and record the details in ‘Calibration record of volumetric glassware” (Bulb/ graduated pipette) Annexure-1.

5.9.6 Acceptance criteria: Refer Annexure–2 for “Acceptance criteria’s of volumetric glassware”.

5.10 Calibration of Burettes Following procedure is applicable for calibration of burettes.

5.10.1 Take clean and dry burette for calibration.

5.10.2 Keep burette and stoppered conical flask containing water at room temperature ( 25 ± 1°C) for about 1 hour.

5.10.3 Clamp the burette vertically on burette stand, check the temperature of waterwith the help of thermometer and ensure that it is 25 ± 1° C.

5.10.4 Fill the burette upto the mark with water.

5.10.5 Set the meniscus at the zero mark using the burette stopcock to lower the water level and touch the tip with wetted wall of a beaker to remove the excess water.

5.10.6 Take a clean and dry stoppered 100 mL conical flask and weigh it accurately (W1).

5.10.7 Place the conical flask under the nozzle, fully open the stopcock until water is  only few mL above 10 mL mark and then the stream is reduced so as to make an accurate setting to 10 mL (Flask shall be at a slight angle).

5.10.8 Close the stopper and take the weight accurately (W2).

5.10.9 Similarly take the weight of water from 10 to 20 mL, 20 to 30 mL, 30 to 40 mL, and  40 to 50 mL accurately.

5.10.10 Calculations:Calculate the actual volume of water, % Error as mentioned in point  No.5.8.4 and  record the details in ‘Calibration record of volumetric glassware” (Annexure-1).

5.10.11 Acceptance criteria :

Refer Annexure–2 for “Acceptance criteria’s of volumetric glassware”.

5.11 Calibration of measuring cylinders

5.11.1 Take clean and dry measuring cylinder to be calibrated.

5.11.2 Keep measuring cylinder and stoppered conical flask containing water at room temperature (25 ± 1°C) for about 1 hour.          

5.11.3 Weigh the empty measuring cylinder accurately (W1).

5.11.4 Check the temperature of water with the help of thermometer; ensure that it is 25 ±1°C.

5.11.5 Fill the cylinder with water (25 ± 1°C) up to the mark.

5.11.6 Adjust the water level such that lowest point of the meniscus with reference to the graduation line is horizontally tangent to the line of upper edge of graduation line with the help of dropper.

5.11.7 Take the weight of filled measuring cylinder accurately (W2).

5.11.8 Calculations: Calculate the actual volume of water, % Error as mentioned in point No.5.8.4 and record the details in “Calibration record of volumetric    

glassware”(Annexure-1) 

5.11.9 Acceptance criteria: Refer Annexure–2 for “Acceptance criteria’s of volumetric glassware”. 

Note : Do not expose volumetric glassware's to HF (Hydrofluoric acid), hot Phosphoric acid, Strong hot alkali and do not  heat above 80°C temperature.

6.0 REFERENCE: NIL

7.0 VERSION HISTORY 

8.0  ANNEXURES

8.1 Annexure-1: Calibration Record of Volumetric Glassware

8.2 Anenxure-2: Acceptance criteria’s of Volumetric Glassware