A common spectroscopy method now achieves accuracy 41 to 87 times better by fixing its own detection errors.

Cavity ring-down spectroscopy is a tool that detects gases by trapping light between mirrors and measuring how fast it fades. But flaws in the detection equipment cause systematic errors, limiting accuracy to a few-percent level, especially when light fades quickly. To fix this, researchers created a system-level detection transfer functiontransfer functionA description of how a system changes an input signal, like light, into an output, like electronic data.. This mathematical model describes how the entire detection setup—including the detector, electronics, and digitizing steps—alters the signal, allowing scientists to correct hidden distortions in gas absorption measurementsabsorption measurementsQuantifying how much light a substance takes in, used to identify or measure gases.. They tested this method on a carbon monoxide absorption line across multiple setups that initially had errors up to 14%. After the correction, every setup agreed, accuracy improved by a factor of 41--87, and errors dropped to the sub-permille level without needing special measurement schemes or external calibration standards.

Why it matters

This improves measurements for tracking atmospheric gases, testing scientific theories, and setting optical standards. More reliable data helps climate science and physics experiments that demand extreme precision.

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