Measurement Deviation
Differences in test results obtained by different facilities using the same procedures and samples reveal the reproducibility of an analytical method. High inter-laboratory variance indicates that a test for pcb material properties or chemical compliance is sensitive to small changes in equipment or environment. This metric is calculated by comparing the standard deviations of results across multiple testing sites.
Root Cause
Discrepancies often arise from variations in the calibration of instruments or the training of the technicians. When inter-laboratory variance is high, a manufacturer may receive conflicting reports on the lead content or glass transition temperature of the same batch of material. Ambient humidity and temperature during the testing process also contribute to these differences.
Systematic round robin testing helps to identify and mitigate these sources of error. The use of a common reference material helps to align the results from disparate locations.
Quality Assurance
Establishing a standard deviation for the industry allows for the creation of realistic acceptance criteria. Efforts to reduce inter-laboratory variance involve the use of standardized samples and detailed protocols that leave little room for interpretation. Reliable data is necessary for the global supply chain to function without frequent disputes over material specifications.
