Thermal F0 Profile Integral

Integrate a sampled thermal profile by trapezoidal lethality at supplied reference temperature and Z value; F0 alone does not validate sterilization.

Description

Equivalent-reference thermal exposure sums temperature-dependent lethality over time.

Equivalent-reference thermal exposure sums temperature-dependent lethality over time. The reference temperature and Z value define the conversion rather than treating every minute as equally effective.^[1]

Integrate a sampled thermal profile by trapezoidal lethality at supplied reference temperature and Z value; F0 alone does not validate sterilization.

When to use Thermal F0 Profile Integral

Use this tool to integrate a sampled thermal profile by trapezoidal lethality at supplied reference temperature and Z value; F0 alone does not validate sterilization.

Prepare the sample, count, growth or assay measurements requested by this tool. Confirm units, sampling periods and reporting bases; supply independently established comparison criteria where requested.

How to use Thermal F0 Profile Integral and understand its results

Prepare the sample, count, growth or assay measurements requested by this tool. Confirm units, sampling periods and reporting bases; supply independently established comparison criteria where requested.
Enter timesMinutes, temperaturesC, referenceTemperatureC, zValueC using the field table and calculation rules, then run the tool.
Read equivalentReferenceMinutes, intervalEquivalentMinutes. 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
timesMinutes	Times minutes	list of number	Required
temperaturesC	Temperatures c	list of number	Required
referenceTemperatureC	Reference temperature c	number	Required
zValueC	Z value c	number	Required

Enter at least two aligned observations with strictly increasing times in minutes, finite temperatures/reference in °C and positive Z in °C. The tool computes lethality at each observation and trapezoidally integrates adjacent rates. Return equivalent reference minutes per interval and their sum.

Paired lists must be nonempty and have equal lengths. Sequences checked for increasing order must be nonempty and strictly increasing; additional calculation rules may require more samples.

lethalRate_i = 10^((T_i−Tref)/Z); intervalMinutes = mean(adjacent rates) × Δtime

Units, indexing, boundary conditions and exceptional cases are defined in the calculation rules above.

Output field	Meaning	Value type
equivalentReferenceMinutes	Equivalent reference minutes	number
intervalEquivalentMinutes	Interval equivalent minutes	list of number

json

{
  "input": {
    "timesMinutes": [
      0,
      2,
      4
    ],
    "temperaturesC": [
      121,
      121,
      111
    ],
    "referenceTemperatureC": 121,
    "zValueC": 10
  },
  "output": {
    "equivalentReferenceMinutes": 3.1,
    "intervalEquivalentMinutes": [
      2,
      1.1
    ]
  }
}

Limitations and assumptions

Integration concerns the supplied profile and interpolated rates, not an unsampled cold spot. Organism resistance, load penetration and process validation are not established by this number; no reference temperature is chosen automatically.

Numeric inputs must be finite. Follow the calculation-specific rules for overflow, underflow and exceptional cases. Lists are limited to 100,000 entries; the rules above may require smaller limits. Missing required fields, extra fields, wrong value types and violations of the calculation rules are input errors.

Alternative or Complementary methods

Use Observed Decimal Reduction Time: Estimate a measured D value from positive viable counts and exposure time under log-linear death assumptions. For a complementary task, use Countable Plate Selection: Select colony-count plates within caller-specified countability limits, retaining low and excessive counts separately.

References

Thermal F0 Profile Integral — tool.io

Similar or alternative tools

Observed Decimal Reduction Time
Estimate a measured D value from positive viable counts and exposure time under log-linear death assumptions.
Countable Plate Selection
Select colony-count plates within caller-specified countability limits, retaining low and excessive counts separately.