Calibration & metrology overview

FreeMaint tracks the calibration of your measuring instruments — both assets (for example a pressure gauge on a machine) and tools (for example a caliper) — in one place. Open Calibration from the sidebar for the register, or use the Calibration tab on any asset or tool.

The calibration register

The register lists every tracked instrument with its live status: in calibration, due soon, overdue, out of tolerance, or limited. Status is derived automatically from the last calibration date and the interval — you never set it by hand. Filter by status and search by name. Viewing the register is available on every plan.

Logging a calibration

From an asset or tool Calibration tab, set up a plan (interval and default tolerance) then log each calibration. A calibration can have several measurement points, each with a nominal value, tolerance limits, and an as-found and an as-left reading.

1. Open the Calibration tab — On the asset or tool, or open the Calibration page and pick the instrument.
2. Set the plan — Enter the interval in days and, optionally, the nominal value and tolerance.
3. Log the calibration — Add the measurement points with their as-found and as-left readings. Pass, fail, adjusted or limited is computed automatically from the readings versus the tolerance.

Certificates and approval

Every record can be exported as a branded, ISO 17025-aligned certificate PDF (instrument details, calibration data, reference-standard traceability, the measurement-points table, and the result). Records can be approved, and on the Enterprise plan the approval can require an electronic signature with re-authentication (21 CFR Part 11). Downloading certificates is available on every plan.

Out-of-tolerance handling

When a calibration comes back out of tolerance, the module can close the loop automatically. Both options are opt-in per instrument and off by default:

• Auto-create a corrective work order, linked back to the record.
• Quarantine the instrument by taking it out of service.
• Reverse-traceability (Enterprise): list every measurement taken with the instrument since its last good calibration, so you can review what may be affected.

Advanced metrology (Enterprise)

On the Enterprise plan the module adds the metrology depth required by ISO 17025, ANSI/NCSL Z540.3 and IATF 16949:

• Measurement uncertainty and Test Uncertainty Ratio (TUR), shown on the certificate.
• Gauge R&R / MSA studies (average-and-range or ANOVA) with %GRR, NDC and an accept / marginal / reject verdict.
• Calibration interval optimization based on the instrument reliability history.
• Drift trending: the as-found deviation of each measurement point over time.

What each plan includes

Viewing the register, instrument history and certificates is free on every plan. Setting up plans and logging calibrations requires the Business plan. The advanced metrology features (uncertainty and TUR, Gauge R&R, interval optimization, drift trending, reverse-traceability and Part 11 e-signature) require the Enterprise plan.