Operation of Digital Micrometer SOP

By / Quality control / QC, SOP /
1.0 OBJECTIVE :
  • To provide a procedure for Operation of Digital Micrometer.
2.0 SCOPE :
  • This procedure is applicable to Mitutoyo make Digital Micrometer.
3.0 RESPONSIBILITY :
  • Quality Control Chemist and above
4.0 ACCOUNTABILITY:
  • Quality Control Head
5.0 PROCEDURE :
  • The Digital Micrometer is a precision instrument that is used to measure thickness of packaging materials like PVC film, aluminum foil etc., accurately.
  • It can measure maximum thickness of 25 mm.
  • Least count of Digital Micrometer is 0.001 mm.

5.1 PRECAUTIONS

  • The Digital Micrometer is a highly heat sensitive instrument and should be stored at room temperature.
  • Hold the Digital Micrometer from its Heat Thermally insulating plate whilst handling to prevent heat transfer from hand of user to the Digital Micrometer.
  • The object to be measured should also be kept at room temperature since this may also affect the reading.
  • Do not over tighten the Digital Micrometer as this can lead to deformation of both the anvil and spindle and the object being measured.
  • Store the Digital Micrometer in its appropriate storage compartment to prevent any wearing of the anvil and/or spindle.
  • Store the Digital Micrometer with the anvil and spindle not in contact with each other so that any temperature fluctuations will not stress the instrument.
  • Measure the desired object three times to ensure that the reading obtained is accurate.
  • Do not operate abruptly, drop or strike the Digital Micrometer.
  • Digital Micrometer uses 1.55V button cell battery.
  • Do not substitute used battery.
  • Discard the used battery.
Mitutoyo Digital Micrometer

5.2 OPERATION

  • Turn the thimble to gently bring the spindle in to contact with the anvil. Apply the rated measuring force using the ratchet stop/friction thimble.
  • Press the zero buttons to zero setting display 0.000 on the screen.
  • Rotate the thimble anticlockwise allowing sufficient space between the anvil and the spindle to accommodate the object to be measured.
  • Place the object to be measured between the anvil and the spindle.
  • Spin the ratchet clockwise until the spindle just meets the object.
  • Keep spinning the ratchet gently until 3 clicks are heard.
  • Check that both the anvil and the spindle are touching the object evenly.
  • Set the Spindle clamp while the micrometer is still on the object.
  • Note the reading.
  • Remove the object from the micrometer.
  • Reset the Spindle clamp to the unlock position.
  • Keep the instrument in box after use.
  • Get calibrated Digital Micrometer by approved outside agency on yearly basis and keep certificate in record.

5.3 CLEANING PROCEDURE

  • Rub off any visible dirt, dust and grit with a lint free cloth.
  • Wipe off the measuring faces of both the anvil and spindle with lint-free paper set the start (zero) point before measuring.
 6.0 ABBREVIATIONS:
AbbreviationExpanded form
mmMillimeter

7.0 ANNEXURES:

Nil

8.0 SOP REFERENCES
  •  Manual of Digital Micrometer

END OF THE SOP