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Standard Calibration Procedure
Test Subject: Depth Micrometer,
Procedure #: QSCP-14
Revision #: 1.0
Approval: James Cagle
1.1 To establish a standard procedure for calibration of Depth Micrometers.
2.1 The calibration laboratory shall be furnished with all items of equipment (including reference materials) required for the correct performance of calibrations and tests. In those cases where the laboratory needs to use equipment outside its permanent control, it shall ensure that the relevant requirements of this section are met.
2.2 All measuring and testing equipment having an effect on the accuracy or validity of calibrations or tests shall be calibrated and/or verified before being put into service. The laboratory shall have an established program for the calibration and verification of its measuring and test equipment. The program will ensure the recall or removal from service of any standard or equipment that has exceeded its calibration interval or is otherwise judged to be unreliable.
2.3 The laboratory shall use appropriate methods and procedures for all calibrations and tests and related activities within its responsibility (including sampling, handling, transport and storage, preparation of items, estimation of uncertainty of measurement and analysis of calibration and/or test data). They shall be consistent with the accuracy required and with any standard specifications relevant to the calibrations or tests concerned.
2.4 The laboratory shall have documented instructions on the use and operation of all relevant equipment, on the handling and preparation of items, and for calibration and/or testing, where the absence of such instructions could jeopardize the calibrations or tests. All instructions, standards, manuals and reference data relevant to the work of the laboratory shall be maintained up-to-date and be readily available to the staff.
3.0 Referenced Documents
3.1 ISO 17025
3.2 NIST Handbook 150
3.3 NIST Technical Note 1297
3.4 ANSI/NCSL Z540-1
3.5 Gagemaker Mic-Trac Manual
4.0 Materials Required
4.1 ZEP ID RED CLEANER
4.2 Hard Arkansas Stone
4.3 Lint free cloth
4.4 Gage oil
4.5 Depth Gage Fixtures (TF-DG)
4.6 Flat faced avils (TF-1F)
4.7 Depth gage support (TF-SS) for rods 6” and up
4.8 5/32” hex wrench
4.9 30 in/lb torque wrench
5.0 Special Precautions
5.1 When adjusting micrometer, do not retract spindle without carefully stoning the OD (if needed), to remove burrs or nicks which may damage the spindle bushing.
5.2 Whenever necessary to disassemble for adjustment, use care with cleanliness to assure no damage to threads.
6.0 Accuracy / Required Range / Measurement Uncertainties
6.1 Accuracy shall be within one scale division.
6.2 Required range shall be within manufacturer specifications.
6.3 If the tolerance is specified by the manufacturer or if there is some functional characteristics that require tolerances other than specified above, these considerations should govern the acceptability of the instrument.
NOTE: where applicable, the methodology of the Guide to Expression of Uncertainty in Measurement 1993 shall be used as the basis for expression of uncertainty of the measurement. Where detailed procedures are not used to quantify and combine uncertainties (i.e. use of test accuracy ratio concepts) the sources of uncertainty shall be tabulated and demonstrated to be acceptable for the measurement undertaken.
7.1 Visually examine the device for any obvious defects that would affect its accuracy or function. Record the “as is” condition of the device onto the instrument records. If discrepancies are noted, discontinue calibration and refer to paragraph 9.1 (Out of Tolerance Conditions).
7.2 Verify that identification marking of the micrometer is distinct and in agreement with the instrument records.
7.4 Clean contact faces with lint free cloth, dampened with cleaning solution.
7.5 If any defects have been found that would affect accuracy or function of the micrometer, discontinue calibration and refer to section 8.0 (Gage Correction).
7.6 Clean exterior surfaces.
7.7 Remove spindle assembly.
7.8 Clean and oil spindle and measuring screw.
7.9 Clean and oil fixed nut in barrel.
7.10 Reassemble micrometer.
7.11 Check measuring screw for wear by pushing the thimble back and forth in direction of measuring screw axis. There should be no reciprocating movement. Adjust for wear if necessary by tightening fixed nut on barrel to a smooth tight (no shake) fit for the full thread length. If it is found that a smooth tight fit can not be achieved due to loose and tight areas on measuring screw, refer to section 8.0 (Gage Correction).
7.12 Set the measuring force for the weight system on the mic-trac to 1lb.
7.13 Mount the Flat face anvils on the receivers of the mic-trac.
7.14 Clean the depth gage fixture and mounting surfaces with ZEP ID Red. Place the fixture against the right receiver pad shoulder with the thumb screws facing to the right.
7.15 Turn the Y Axis adjust knob counterclockwise until the face of the depth gage fixture touches the flat face anvil.
7.16 Start Certifi’s read out display.
7.17 Clean the depth micrometer using the cloth and ZEP ID cleaner.
7.18 Zero the depth micrometer on a flat surface.
7.19 Retract the thumbscrews on the depth gage fixture enough to fit the micrometer and mount it aligning the rod with the center of the flat face anvil.
7.20 Secure the micrometer by holding down on the base and tightening the thumb knob on each side of the depth gage fixture.
7.21 Enter all client information in Certifi, as would be needed in their certification.
7.22 Adjust the depth micrometer to the first calibration value. If you pass the calibration value, turn the spindle back and approach the value again, from the same direction. This practice will increase the accuracy of the calibration.
7.23 Continue measuring the depth micrometer until the values for the first depth rod are recorded in Certifi.
7.24 Load the depth gage support fixture for any rods longer than 6”.
8.0 Gage Correction
8.1 Any gage exceeding specified tolerances per section 6.0 at any time during calibration shall be repaired and re-calibrated, returned as is for restricted use or scrapped.
9.0 Out of Tolerance Conditions
9.1 If any instruments are found to be significantly out of tolerance during the calibration/verification process, the supplier’s system shall provide for notification to the user and to the supplier’s quality element. If appropriate, state the out of tolerance condition with the associated measurement data so that appropriate action can be taken.
10.1 The records for instruments requiring calibration shall include an individual record of calibration or verification, or other means of control. This record shall provide a description or identification of the item, calibration interval, date calibrated, identification of the calibration source, calibration results (data and/or condition status) and calibration action taken (adjusted, repaired, new value assigned, de-rated, etc.).
11.0 Calibration Status
11.1 Instruments shall be labeled to indicate calibration or verification status. The label shall identify specific date calibrated (date, month, year, Julian date, or equivalent) and the specific calibration due date or usage equivalent. Items not calibrated to their full capability or which have other limitations of use, shall be labeled or otherwise identified as to the limitations. When it is impractical to apply a label directly to an item, the label may be affixed to the instrument container or some other suitable means may be used to reflect calibration status. Tamper resistant seals are affixed to operator accessible controls or adjustments, which if moved will invalidate the calibration. The quality system shall provide instructions for disposition of equipment with broken tamper resistant seals.
12.0 Storage and Handling
12.1 Instruments shall be handled, stored, and transported in a manner which shall not adversely affect the calibration or condition of the equipment.
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QualiCal, LLC - Quality Management System - Calibration Procedures