Detection limit

The limit of detection (english limit of detection, LOD, or lower detection limit, LDL ) denotes the extreme value of a measurement method, to which the measured variable can just be detected reliably ( yes / no decision).

The measured value at the detection limit has increased inaccuracy, but does not exceed a given statistical confidence interval. Values ​​( issues ), which have a greater uncertainty than the predetermined interval beyond the limit of detection and are referred to in the sense of measuring technology as unmeasurable or undetectable.

The criterion of " reliable detection " is generally based on the precision of the measurement method for measuring a zero or null measurement. This refers to the statistical error or the fluctuation of the measured signal when no sample is present (eg, the standard deviation of the background signal or blank).

Often a measurement is considered as proof when the measurements are at least three standard deviations above the baseline measurement.

• : Mean value of the blank value
• : Standard deviation of the blank value