The analyte was not detected or was below a specific threshold
(e.g., 3.6 is the limit, and the result is somewhere below it.

The true value exceeds the reporting or calibration range.

Specifically for instrumental "not detected" results where no
signal was distinguishable from noise.

The instrument sensor was overloaded (saturated) by the signal,
meaning the reported value is the maximum "clipped" output and the true
value is likely much higher.

The lowest concentration that can be identified with 99%
confidence as being greater than zero..

The result is likely an underestimate of the true value due to
known systematic error (e.g., sample loss).

The result is likely an overestimate (e.g., due to contamination
or interference).