Detection Limit
Estimate LOD from a measured standard concentration and target signal-to-noise ratio.
Description
A signal-to-noise detection-limit estimate assumes response scales linearly with concentration.
A signal-to-noise detection-limit estimate assumes response scales linearly with concentration. The required S/N scales a known concentration by the observed ratio.1
Estimate LOD from a measured standard concentration and target signal-to-noise ratio.
When to use Detection Limit
Use this tool to estimate LOD from a measured standard concentration and target signal-to-noise ratio.
Prepare the measured profile, formula counts, upstream model outputs or caller-defined reference criteria requested. Keep paired entries aligned and units, sample basis and preprocessing consistent.
How to use Detection Limit and understand its results
- Prepare the measured profile, formula counts, upstream model outputs or caller-defined reference criteria requested. Keep paired entries aligned and units, sample basis and preprocessing consistent.
- Enter knownConcentrationUmol, measuredSignalToNoise, requiredDetectionSnr using the field table and calculation rules, then run the tool.
- Read detectionLimitUmol. The explanation below defines the units, signs, ordering and any flags or placeholder values.
- If the tool reports an input issue, correct the values and run it again. Apply the stated assumptions when interpreting a successfully returned result.
| Input field | Meaning | Value type; see rules below | Requirement |
|---|---|---|---|
| knownConcentrationUmol | Known concentration umol | number | Required |
| measuredSignalToNoise | Measured signal to noise | number | Required |
| requiredDetectionSnr | Required detection snr | number | Required |
Enter positive concentration in µmol, measured S/N and required S/N. Return estimated concentration limit.
limit=knownConcentration×requiredSnr/measuredSnr Units, indexing, boundary conditions and exceptional cases are defined in the calculation rules above.
| Output field | Meaning | Value type |
|---|---|---|
| detectionLimitUmol | Detection limit umol | number |
{
"input": {
"knownConcentrationUmol": 10,
"measuredSignalToNoise": 20,
"requiredDetectionSnr": 3
},
"output": {
"detectionLimitUmol": 1.5
}
}Limitations and assumptions
No calibration fit, blank distribution or method validation is performed.
Numeric inputs must be finite. Follow the calculation-specific rules for overflow, underflow and exceptional cases. Missing required fields, extra fields, wrong value types and violations of the calculation rules are input errors.
Alternative or Complementary methods
Use Quantification Limit: Estimate concentration LOQ from calibration slope, blank noise, and a supplied S/N criterion. For a complementary task, use Baseline Noise Snr: Estimate baseline noise and signal-to-noise from a sampled segment.
References
-
Detection Limit — tool.io
Similar or alternative tools
- Quantification Limit
Estimate concentration LOQ from calibration slope, blank noise, and a supplied S/N criterion.
- Baseline Noise Snr
Estimate baseline noise and signal-to-noise from a sampled segment.