# Method Validation & Measurement Uncertainty Record

> ISO/IEC 17025:2017 (lab competence) – cl.7.2 method selection/
> verification/validation + cl.7.6 measurement uncertainty (MU).
> Required before a lab reports results under accreditation.

| Field | Value |
|-------|-------|
| Method | name/SOP ref |
| Validation ID | VAL-YYYY-NNN |
| Analyst | @name |
| Approved by | technical manager |

## 1. Method identification

- Standard method (verified) or non-standard/lab-developed (validated)
- Scope: analytes, matrices, measurement range

## 2. Performance characteristics validated

| Characteristic | Experiment | Acceptance criterion | Result | Pass? |
|----------------|------------|----------------------|--------|-------|
| Selectivity | interference check | no interference >N% | | |
| Linearity | N-point calibration | R2 ≥ 0.99N | | |
| LOD/LOQ | repeated blanks | LOD ≤ N | | |
| Precision (repeatability) | n≥N replicates | %RSD ≤ N | | |
| Reproducibility | analyst/day variation | %RSD ≤ N | | |
| Trueness/bias | CRM or spike recovery | N-N% recovery | | |
| Robustness | parameter variation | stable within N% | | |

## 3. Measurement uncertainty budget (cl.7.6)

$$U = k \cdot u_c, \quad u_c = \sqrt{\sum_i u_i^2}$$

| Component $u_i$ | Type | Value | Distribution | Contribution |
|-----------------|------|-------|--------------|--------------|
| Calibration | B | | normal | |
| Repeatability | A | | normal | |
| Purity of standard | B | | rectangular | |
| **Combined $u_c$** | | | | |
| **Expanded $U$ (k=2, 95%)** | | | | |

## 4. Quality control ongoing

- Control charts (Shewhart) per batch, acceptance rules
- PT/ILC participation – proficiency testing records

## 5. Reporting statement

Result reported as: value ± U (k=2) per scope of accreditation.