Air Sample Duration Share Tool

Description

Return share = includedDuration/recordedDuration and defined = true when recordedDuration > 0; otherwise return share = 0 and defined = false.

Environmental monitoring coverage depends on what counts in the denominator. Time, effort, area, sampled volume and exposure weights describe different support measures; excluding missing or ineligible portions changes the question answered by a fraction.

Return share = includedDuration/recordedDuration and defined = true when recordedDuration > 0; otherwise return share = 0 and defined = false.

When to use this tool

Use Air Sample Duration Share when checking a monitoring or sampling share with an explicit inclusion and overlap convention.

How to use the tool and how it works

Enter includedDuration, recordedDuration. Use the units and conventions below.
Run the tool. Correct any format, range, or cross-field input error before interpreting the output.
Read share, defined. Inspect defined before interpreting the associated values.

Require 0 <= includedDuration <= recordedDuration. Return share = includedDuration/recordedDuration and defined = true when recordedDuration > 0; otherwise return share = 0 and defined = false. Durations must use one time unit.^[1]

Input field	Meaning and units	Accepted input
includedDuration	Included Duration	Required. Finite number; minimum 0.
recordedDuration	Recorded Duration	Required. Finite number; minimum 0.

Output field	Interpretation	Returned shape
share	Dimensionless selected contribution divided by the stated total; not a percentage.	Required. Finite number.
defined	Whether the denominator is positive and the returned ratio is defined; inspect this before using a zero placeholder.	Required. Boolean.

json

{
  "input": {
    "includedDuration": 3,
    "recordedDuration": 12
  },
  "output": {
    "share": 0.25,
    "defined": true
  }
}

Limitations and assumptions

The zero-duration ratio is undefined. This is a time inclusion share, not concentration coverage, breathing dose, data quality or proof that a monitoring protocol was followed.
Inputs must satisfy both the field types and the cross-field conditions above. Invalid input causes an error; a successful false flag or documented placeholder is a different result.
Numeric calculations use binary floating point unless exact decimal-integer arithmetic is explicitly stated. No hidden measurement tolerance or decimal rounding is added; nonfinite or out-of-contract results are rejected. Numeric signed-zero results are exported as zero.

Alternative or Complementary methods

Review source intervals and sampling design, and compute overlaps from actual records when an aggregate deduction cannot be justified.

References

Calculation and input contract: environmental-health/air-sample-duration-share — tool.io

Similar or alternative tools

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