SOP Title: Operation and Calibration of Micrometer Screw Gauge

SOP Title: Operation and Calibration of Micrometer Screw Gauge

1. Objective:

To lay down the procedure for Operation and Calibration of Micrometer Screw Gauge.

2. Scope:

This SOP is applicable for Operation, Cleaning and Calibration of Micrometer Screw Gauge located in Quality Control Laboratory.

 

3. Responsibility:

• Quality Control: To prepare and review the SOP. To follow the procedures laid down for Operation and Calibration of Micrometer Screw Gauge as per this SOP.
• Quality Assurance Department: To review and approve the SOP and Annexures.

 

4. Accountability:

Head Quality Control Department, Head Quality Assurance Department.

5. Procedure:

 

5.1	Safety Precautions/Instructions:
5.1.1	Wear personal protective equipments such as hand gloves during operation of micrometer screw gauge.
5.2	Operation:
5.2.1	Range of the instrument is 0 to 25 mm & least count is 0.001mm.
5.2.2	There are three scale readings on micrometer screw gauge.
5.2.3	Main scale range is 0 to 25 mm, circular scale range is 0 to 50 and coincide scale range is 0 to 10.
5.2.4	Loosen the small screw provided by pushing it right side.
5.2.5	First adjust the circular scale to the 0 reading.
5.2.6	0 on the main scale should coincide with the 0 of circular scale reading.
5.2.7	Then carefully insert the sample into the micrometer screw gauge by rotating the circular scale knob to hold firmly.
5.2.8	First note down the reading on the main scale.
5.2.9	Then note down the reading on circular scale which is coinciding with the division on the coincide scale.
5.2.10	Calculate the thickness of the sample using the formula: Main scale reading + (circular scale x least count)
5.2.11	Example: If main scale reading is 1 mm and circular scale reading coinciding is 44 then by applying formula, thickness of the sample is, 1 + (44 x 0.001)  = 1.044 mm.
5.2.12	Remove the sample and bring the instrument in its initial position.
5.3	Calibration Procedure:
	Frequency:  Once in a year by external agency.
5.3.1	Calibration is carried out by external agency as per SOP “Calibration of Instruments and Equipments”.
5.3.2	Refer Annexure for calibration test to be performed and acceptance criteria. Sr. No. Tests Set value Acceptance Criteria (mm) 1. Gauge size 2.5 mm ± 0.004 5.1 mm ± 0.004 7.7 mm ± 0.004 10.3 mm ± 0.004 12.9 mm ± 0.004 15.0 mm ± 0.004 17.6 mm ± 0.004 20.2 mm ± 0.004 22.8 mm ± 0.004 25.0 mm ± 0.004
5.3.3	Generate the A. R. No. on the “Instrument/Equipment Calibration Register” as per SOP and give requisition to QA department for calibration formats of instruments/equipments on the due date of calibration.
5.3.4	For issuance of calibration report refer SOP “Control of documents, Preparation, Approval, Issuance and Maintenance.
5.3.5	Update “Annual Calibration Schedule” and “Monthly Calibration Schedule” as per SOP No “Calibration of Instruments and Equipments”.
5.3.6	If any breakdown occurs, follow procedure as per SOP “Calibration of Instruments and Equipments”.

 

 

6. Definitions / Abbreviations:

• Definitions:
• Breakdown: Any activity leading to operation of instrument/equipment other than the set parameters or unusual sound or vibration observed in the instrument/equipment.
• Calibration: Tests performed to ensure that the instrument/equipment is functioning as per set parameters. These tests are performed as per predefined frequency and also after any major repair or replacement of parts.

 

• Abbreviations:

Abbreviation	Expansion
SOP	Standard Operating Procedure
QC	Quality Control
QA	Quality Assurance
A. R. No	Analytical Reference Number
No.	Number
mm	millimetre
PM	Preventive Maintenance

 

*Note – Ready to use SOP available in “DOWNLOAD” Section.