interlaboratory comparison

**Interlaboratory Comparison** is a **quality assurance exercise where multiple laboratories measure the same sample and compare their results** — evaluating measurement consistency across different labs, instruments, operators, and methods to identify systematic biases and validate measurement capabilities. **Comparison Types** - **Round Robin**: The same sample circulates among participating labs — each lab measures and reports results. - **Proficiency Testing (PT)**: An external organization distributes samples, collects results, and evaluates lab performance. - **Bilateral**: Two labs compare results — typically a reference lab and a production lab. - **Key Comparison**: BIPM-organized comparisons among national metrology institutes — establishing international equivalence. **Why It Matters** - **Consistency**: Ensures measurements from different labs are comparable — essential for global manufacturing and supply chains. - **Accreditation**: ISO 17025 requires participation in interlaboratory comparisons — mandatory for accredited labs. - **Bias Detection**: Identifies labs with systematic biases — enables corrective action before results are compromised. **Interlaboratory Comparison** is **the measurement cross-check** — ensuring different laboratories produce consistent, reliable results through systematic comparison exercises.