Sedgwick Rafter Cell Density Calculator
Estimate actual Sedgwick–Rafter counted-field density using measured field areas/chamber depth and dilution; no assumed full-cell volume, sampling variance or organism identification.
Description
Counting-chamber density depends on the volume actually examined.
Counting-chamber density depends on the volume actually examined. Unequal field areas require volume pooling rather than an assumed full chamber.1
Enter aligned nonempty nonnegative integer counts/positive field areas, positive chamber depth and dilution≥1. Return examined volume and original-sample estimated cells/mL.
When to use Sedgwick Rafter Cell Density Calculator
Use Sedgwick Rafter Cell Density Calculator when you need to evaluate the supplied records under the calculation and evidence rules below. No organism identification, sampling variance or universal chamber volume is assumed.
Prepare the observed lake or sample measurements and explicit calibration, reference values or thresholds requested. Keep depth coverage, units, dates and sampling conditions consistent.
How to use Sedgwick Rafter Cell Density Calculator and understand its results
- Prepare the observed lake or sample measurements and explicit calibration, reference values or thresholds requested. Keep depth coverage, units, dates and sampling conditions consistent.
- Enter observedCellCounts, observedFieldAreasMm2, chamberDepthMm, sampleDilutionFactor using the field table and calculation rules, then run the tool.
- Read observedCountedVolumeMl, estimatedOriginalCellDensityPerMl. 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 |
|---|---|---|---|
| observedCellCounts | Observed cell counts | list of number | Required |
| observedFieldAreasMm2 | Observed field areas mm2 | list of number | Required |
| chamberDepthMm | Chamber depth mm | number | Required |
| sampleDilutionFactor | Sample dilution factor | number | Required |
Enter aligned nonempty nonnegative integer counts/positive field areas, positive chamber depth and dilution≥1. Return examined volume and original-sample estimated cells/mL.
countedMl=sum(fieldAreaMm²)×depthMm/1000; originalDensity=sum(counts)×dilution/countedMl Units, indexing, boundary conditions and exceptional cases are defined in the calculation rules above.
| Output field | Meaning | Value type |
|---|---|---|
| observedCountedVolumeMl | Observed counted volume ml | number |
| estimatedOriginalCellDensityPerMl | Estimated original cell density per ml | number |
{
"input": {
"observedCellCounts": [
10,
20
],
"observedFieldAreasMm2": [
1,
2
],
"chamberDepthMm": 1,
"sampleDilutionFactor": 2
},
"output": {
"observedCountedVolumeMl": 0.003,
"estimatedOriginalCellDensityPerMl": 20000
}
}Limitations and assumptions
No organism identification, sampling variance or universal chamber volume is assumed.
Numeric inputs, where present, must be finite. Follow the calculation-specific rules for overflow, underflow and exceptional cases. Numeric lists are limited to 10,000 entries; string lists to 128 strings of at most 128 characters each. The rules above may impose smaller limits. Missing required fields, extra fields, wrong value types and violations of the calculation rules are input errors.
Alternative or Complementary methods
Use Plankton Settling Volume Liter Calculator: Settled plankton volume is an operational measurement. Blank subtraction can produce negative estimates that should remain visible. For a complementary task, use Zooplankton Length Weight Regression Calculator: Zooplankton mass can be fitted as a power of length for a defined taxon and measurement basis. Log-linear fitting predicts a conditional median on the mass scale.
References
-
Sedgwick Rafter Cell Density Calculator — tool.io
Similar or alternative tools
- Plankton Settling Volume Liter Calculator
Settled plankton volume is an operational measurement. Blank subtraction can produce negative estimates that should remain visible.
- Zooplankton Length Weight Regression Calculator
Zooplankton mass can be fitted as a power of length for a defined taxon and measurement basis. Log-linear fitting predicts a conditional median on the mass scale.