1.0 OBJECTIVE:
1.1 To describe the procedure for the operation of the Vernier Caliper for measuring the thickness, diameter, length and width of tablets.

2.0 SCOPE:
2.1 This SOP shall apply to the operation of the Vernier Caliper used in the Quality Control Laboratory for measurement of tablet dimensions during in-process and finished product testing.

3.0 RESPONSIBILITIES:
3.1 Designee Production / Quality Assurance (QA) / Quality Assurance (QC):
3.1.1 Operation, cleaning and documentation.
3.1.2 Shall verify the instrument status before use.
3.1.3 Shall operate the instrument in accordance with this SOP.
3.1.4 Shall record the observations and test results.
3.1.5 Shall clean the instrument after completion of analysis.

3.2 Department Head:
3.2.1 Overall compliance.

3.3 QA Department:
3.3.1 Periodic verification and SOP compliance.

4.0 DEFINATIONS:
4.1 Vernier Caliper: A precision measuring instrument used to determine the external dimensions of tablets, including thickness, diameter, length and width.

4.2 Thickness: The distance measured between the upper and lower surfaces of a tablet.

4.3 Diameter: The distance measured across the circular face of a round tablet.

4.4 Length: The maximum longitudinal dimension of an oblong or capsule-shaped tablet.

4.5 Width: The dimension measured perpendicular to the tablet length.

5.0 PROCEDURE:
5.1 Before Operation:
5.1.1 The designee shall verify that the Vernier Caliper is clean, calibrated and bears a valid calibration label before use.

5.1.2 The designee shall inspect the measuring jaws for cleanliness and damage.

5.1.3 The designee shall close the measuring jaws completely and verify that the display or scale indicates zero. If required, the instrument shall be zeroed before use.

5.1.4 The designee shall ensure that the tablet sample and approved analytical method are available before measurement.

5.2 Measurement of Tablet Thickness:
5.2.1 The tablet shall be placed centrally between the external measuring jaws.

5.2.2 The measuring jaws shall be closed gently until they just contact both tablet surfaces without applying excessive pressure.

5.2.3 The tablet thickness shall be read directly from the display or scale.

5.3 Measurement of Tablet Diameter:
5.3.1 The tablet shall be positioned between the external measuring jaws across its widest circular surface.

5.3.2 The measuring jaws shall be closed gently until they contact the tablet.

5.4 Measurement of Tablet Length:
5.4.1 The tablet shall be positioned longitudinally between the external measuring jaws.

5.4.2 The measuring jaws shall be closed gently until they contact both ends of the tablet.

5.5 Measurement of Tablet Width:
5.5.1 The tablet shall be rotated through 90° from the length position.

5.5.2 The width shall be measured using the external measuring jaws.

5.6 Cleaning:
5.6.1 The measuring jaws shall be cleaned using a clean, dry, lint-free cloth after completion of analysis.

5.6.2 Any powder residue shall be removed carefully without scratching the measuring surfaces.

5.6.3 Water, organic solvents and abrasive cleaning materials shall not be used unless recommended by the manufacturer.

5.6.4 The Vernier Caliper shall be closed gently after cleaning and the instrument shall be stored in its protective case after use.

6.0 REFERENCE:
6.1 Instrument User Manual

6.2 British Pharmacopoeia / US Pharmacopoeia

7.0 RECORDS:
Sr No. Title Nature of Document Document No.
NA NA NA NA

8.0 REVISION HISTORY:
Amendment Date: Update Summary Version No.
NA New SOP 01