QP-7.6 Control of Monitoring and Measuring Equipment

Revision F · Effective 2025-04-21

1 Purpose

This procedure ensures that every gage, instrument and measuring machine used to accept product is identified, calibrated at a defined interval against traceable standards, protected from damage and invalid adjustment, and that product is evaluated when a gage is found out of tolerance.

2 Scope

Applies to all measuring equipment used for product acceptance at the Wichita plant, including company-owned gages, personal tools brought in by employees or contractors, the coordinate measuring machines CMM-01 and CMM-02 in the Bay 4 metrology lab, and customer-owned gages. Reference-only equipment that is never used to accept product is labeled "REFERENCE ONLY - NO CAL REQUIRED" and is excluded.

3 Definitions

• Gage ID - a unique number in the format GA-nnnn (for example GA-0147) engraved or labeled on the gage and recorded in the calibration database.
• Calibration Record - F-760-01, the record of each calibration event, including as-found and as-left readings.
• OOT - out-of-tolerance; a gage whose as-found reading is outside its accuracy limit.
• OOT Investigation - F-760-02.

4 Responsibilities

• Quality Engineer (Tomas Reyes) - owns this procedure, sets calibration intervals, leads OOT investigations.
• Quality Technician (Dana Whitfield) - maintains the calibration database, performs in-house calibrations, recalls gages that are coming due, and coordinates outside calibration.
• Users - check the label before use, protect gages from damage, and return gages for calibration when recalled.

5 Procedure

5.1 Enrollment

Every gage is enrolled in the calibration database and given a GA-nnnn ID before first use on product. Personal tools (for example an employee's own calipers or micrometers) must be enrolled and calibrated before they are used on product, and are subject to the same intervals and recall as company gages. Unenrolled tools found in use on product are removed and the work they accepted is reviewed under 5.6.

5.2 Calibration intervals

Equipment	Interval	Performed by
Hand tools: calipers, micrometers, dial and test indicators	12 months	In-house, Bay 4 lab
Pin gages and thread gages	24 months	In-house or accredited provider
Torque wrenches	6 months	In-house torque analyzer
CMMs (CMM-01, CMM-02)	Annually	ISO/IEC 17025 accredited provider
Gage blocks and reference standards	24 months	ISO/IEC 17025 accredited provider

The Quality Engineer may shorten an interval after an OOT result. Intervals are lengthened only with two consecutive in-tolerance calibrations and Quality Manager approval.

5.3 Calibration environment and traceability

In-house calibrations are performed in the Bay 4 metrology lab at 20 +/- 1 C, using reference standards calibrated by an ISO/IEC 17025 accredited provider with traceability to NIST. Gages are allowed to stabilize in the lab before calibration. Outside calibration certificates are reviewed by the Quality Technician for as-found data, uncertainty and accreditation before the gage is returned to service.

5.4 Status labels

Label	Meaning
Green	Calibrated; shows gage ID, calibration date, due date and technician initials.
Yellow	Limited use; the restriction (for example "0-25 mm only" or "not for final acceptance") is written on the label.
Red	Do not use; overdue, damaged, failed calibration or awaiting OOT investigation.

A gage past its due date is treated as red even if the label has not been changed.

5.5 Recall

The Quality Technician runs the due list from the calibration database every Monday and recalls gages due within the next 14 days. Production supervisors return recalled gages to Bay 4. Gages that cannot be located are marked "missing" in the database and reported to the Quality Engineer.

5.6 Out-of-tolerance investigation

When a gage is found OOT at calibration, or is dropped, damaged or suspected of being inaccurate:

1. The gage is red-labeled and removed from use.
2. The Quality Engineer opens an OOT Investigation (F-760-02) within 5 working days.
3. The investigation assesses product impact back to the last good calibration, using the calibration database and the ERP to identify every job inspected with the gage in that period.
4. Product that may be affected and is still at Tallgrass is placed on hold per WI-610 and re-inspected. If affected product has shipped, it is handled as an escape under QP-7.5, including customer notification.
5. The result and actions are recorded on F-760-02 and signed by the Quality Manager.

5.7 Handling and storage

Gages are stored in their cases or on designated shadow boards. Adjustable gages with locked settings are sealed with a tamper label; a broken seal makes the gage red until it is recalibrated. CMM operation, probe qualification and part soak times are covered in WI-210.

6 Records

Calibration Records (F-760-01), outside calibration certificates and OOT Investigations (F-760-02) are quality records retained 10 years from creation per QP-4.2. The calibration database is backed up per IT-07.

7 Revision history

Rev	Date	Change	Approved by
D	2019-01-28	Added colored status labels.	Ruth Okafor
E	2022-03-07	Torque wrench interval changed to 6 months; added F-760-02.	Ruth Okafor
F	2025-04-21	Personal tools must be enrolled and calibrated before use; OOT investigation due within 5 working days; weekly recall run added.	Ruth Okafor