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What should QA check on TMDE calibration?

Calibration checks come down to traceability, labels, and the schedule. Test, measurement and diagnostic equipment is calibrated and certified through a chain that runs back to the primary standards laboratory and ultimately to NIST, the certification label on the item is the authority for when it is next due, and only the precision measurement laboratory may determine and sign an item's condition tag. The rest is verifying each item against the master listing and confirming the work centre is watching its own due dates.

Readers asked this on CheckMyRegs and CheckMyAFI 14 times — this page answers it from the official catalogs and the publications’ own text.

The controlling publication in each branch

BranchControlling publicationDatedSource
Air ForceDAFI 21-101 Current
TMDE flight, calibration traceability and handling
2023-12-20Official link
ArmyAR 750-1 Current
Army TMDE programme objectives and interval analysis
2026-04-29Official link
Marine CorpsMCO 4733.1D Current
Marine Corps TMDE Calibration and Maintenance Program
Official link
NavyOPNAVINST 4790.2K Current
Naval Aviation Maintenance Program equivalent
2025-04-25Official link
Publication numbers, dates, and statuses resolve live against each branch’s official catalog every time this page loads — when a service revises its reg, this page follows. Quotes below are extracted verbatim from the official PDFs. Verify the controlling copy before citing it.

What the regulation actually says

Traceable to NIST

The TMDE flight maintains, calibrates and certifies equipment through a chain traceable via the Air Force Primary Standards Laboratory to the National Institute of Standards and Technology — traceability is the property being certified.

“4.12. Test, Measurement, and Diagnostic Equipment ( TMDE) Flight. Maintains, calibrates, and certifies TMDE, traceable through the AF Primary Standards Laboratory (AFPSL) to the National Institute of Standards and Technology (NIST), or other AF Metrology and Calibration (AFMETCAL)-approved source. Provides base -level support of aircraft, precision -guided munitions, ground systems, and other equipment assigned to the base or GSU. TMDE Flight ensures Calibration, certification, and maintenance of TMDE is accomplished IAW AFMAN 21- 113, TO 00 -20-14, TO 33K-1-100-1, Calibration Procedure for Maintenance Data Collection Codes and Calibration Measurement Summaries. A Rapid Assistance Support for Calibration may also be assigned.”

The label is the authority

Physically check every item against the work centre master identification listing for identification number, serial number and date due calibration; the certification label on the item is the authority for that due date.

“4.3.1. Physically check each item of TMDE against the OWC Master ID Listing for ID number, serial number, a nd date due calibration. The certification label on the TMDE is the authority for the date due.”

Only the lab signs condition

TMDE condition can only be determined by the precision measurement equipment laboratory, so every condition tag must be signed by laboratory personnel and not by the using work centre.

“26. Condition Tags. TMDE condition can only be determined by PMEL; therefore, all TMDE condition tags must be signed by PMEL personnel. RONALD G. ALLEN, JR., Colonel, USAF Commander Attachment 1 GLOSSARY OF REFERENCES AND SUPPORTING INFORMATION References FAR 66-1, Maintenance Management Policy. MACRO 66-1, Maintenance Management Policy. T.O. 00-20-14, Air Force Metrology and Calibration Program. T.O. 00-25-234, General Shop Practice Requirements for the Repair, Maintenance, and Test of Electronic Equipment. T.O. 00-35D-54, USAF Deficiency Reporting and Investigation System. T.O. 11H4-1-1, Periodic Inspection and Certification of Federal Stock Class (FSC) 6665 Equipment and Standards. T.O. 15X-1-102, General Care and Use of Oxygen Gauges and Oxygen Test Equipment. T.O. 33K-1-100-1 and 33K-1-100-2, TMDE Interval, Calibration and Repair, Technical Order Guide and Work Unit Code Manual.”… (paragraph continues in the PDF)

Handling is part of it

Proper calibration, use, care, handling and transportation of TMDE all fall under the same technical order and metrology programme guidance, so damage in transit is a compliance issue and not just bad luck.

“2.10.11. Ensure proper calibration, use, care, handling and transportation of Test Measurement and Diagnostic Equipment ( TMDE) IAW TO 00-20-14 and AFMAN 21-113, Air Force Metrology and Calibration (AFMETCAL) Program Management , and applicable Calibration Measurement Summaries.”

Watch the schedule

Work centre supervisors review their maintenance data collection equipment schedule to identify priority items coming due, and the coordinator contacts the scheduler before the item is due rather than after.

“12.2. Work center supervisors will review their OWC’s maintenance data collection (MDC) equipment schedule to identify priority TMDE due scheduled calibration. The TMDE coordinator will contact the TMDE scheduler before TMDE is due calibration.”

Flag the clashes

Monitors review the schedule for mission-essential equipment and contact the scheduler when like items are due within fifteen duty days of one another, so a whole capability does not go to the lab at once.

“5.2. TMDE monitors/coordinators and work center supervisors are responsible for reviewing their equipment schedules (part III) for mission essential TMDE. Contact the TMDE scheduler if like items of mission essential TMDE are due within 15 duty days of one another, or may interfere with exercises, inspections, TDYs, or other unique requirements. The TMDE monitor/coordinator must coordinate with the TMDE scheduler 5 duty days in advance. This will ensure that calibration resources will be available to support mission - essential TMDE due calibration.”

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Updated 2026-08-01. CheckMyRegs is an unofficial index — always cite the official publication.