The register is one line per instrument used to accept product or control a process. It is not an asset list, and it is not only a due-date list. Each line answers four questions: what is it, where is it, when is it due, and what would a failure put at risk.
What goes on it
- Every instrument used for product acceptance, in-process control, first article, setup of a feature, or process monitoring that a product decision rests on.
- Employee-owned tools used on product. They are recalled like company tools, or they stay off the floor.
- Customer-owned and customer-specified equipment, with the customer's own interval and acceptance rules.
- Reference standards and setting masters: gauge blocks, ring and plug masters, surface plates, artifacts.
- Measuring software and programs where they decide acceptance: CMM programs, vision recipes, test routines (see chapter 12).
- Instruments used only for reference or rough work are either on the register marked for that use, or physically marked so they cannot be mistaken for controlled ones ('Reference only: not for acceptance').
The columns that matter most
| Column | Why it matters | How we fill it |
|---|---|---|
| Used for (parts and characteristics) | Turns an out-of-tolerance result into a list of parts in question | Part numbers and features, or part families and the operation |
| Measurement risk | Tells you how far a failure reaches and how hard to watch it | High for final acceptance and key characteristics; medium for in-process control; low for setup and reference |
| Interval | Sets the recall | From the starting points in chapter 7, then the as-found history |
| Last result (as found) | The only result that says whether past measurements can be trusted | From the certificate, before any adjustment |
| Last known good | Starts the window of an impact assessment | The last date it was shown within limits, as found or as left |
| Impact assessment and reference | Shows the auditor the out-of-tolerance path works | Open, Closed or Not needed, with the assessment number |
| Gauge study on file? | Separates calibrated from capable | Yes, No, or Not needed for this use, matching the MSA plan |
Identification and status
Each instrument carries its ID permanently and a status label that shows it is fit for use: calibrated and when it is due, or limited (with the limitation written on it), or reference only. Instruments that are out of calibration, damaged or awaiting an assessment go into a marked quarantine area, not back in a drawer. Where a label will not survive (small gauges, ring masters), use the ID and the register, and keep the gauge in its own marked case.
Receiving a new instrument
- A unique ID assigned and marked on the instrument (never a reused number)7.1.5.2
- Calibrated before first use, new or not, with as-found data and traceability on the certificate7.1.5.2
- Resolution and accuracy suit the tightest tolerance it will check7.1.5.1
- Register line complete: use, measurement risk, owner, location, interval7.1.5.2
- Interim check defined where the measurement risk is high7.1.5.1
- Added to the MSA plan if it will accept a key characteristic or feed a capability number7.1.5.1
- Users shown how to set, check and read it7.2
Answer each: Yes / No / N/A, with your notes and evidence. The Word and fillable PDF handbook have the check boxes.
Retiring, losing or replacing an instrument
An instrument leaves the system as carefully as it entered. Before it is retired, it gets a final calibration or check where it was used for acceptance since its last calibration, so the last window is closed. Its register line is marked Retired with the date and reason, never deleted, and its ID is never reused. A lost instrument is treated like one that failed: the window since last known good is assessed, because nobody can show it was good when it was last used. A replacement gets a new ID and its own line, and inherits any gauge study only if it is the same model used the same way, which the MSA plan should record.
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A management aid, not certification or a registrar audit. Using it does not by itself show conformity to AS9100D or any other standard, and your customers' requirements may add to it.
Clause numbers refer to AS9100D (SAE AS9100 Rev D) unless another document is named. The standards' text is not reproduced here: use your own licensed copy.
Aegis Insights are our own guidance, labeled wherever they appear: how we approach this work, not a requirement of any standard or customer.