IEC 61672 Class Reference
Return the practical distinction and limitations of Class 1 and Class 2 sound-level meters.
Description
IEC 61672 Class 1 instruments have tighter tolerance limits and a wider specified frequency range than Class 2 instruments.
IEC 61672 Class 1 instruments have tighter tolerance limits and a wider specified frequency range than Class 2 instruments. This reference explains the selected concept and the evidence needed to interpret it.1
The returned values include Source, Statement, Topic. The How section below explains the calculation, input rules and interpretation.
When to use IEC 61672 Class Reference
Use IEC 61672 Class Reference when you need to evaluate the supplied records under the calculation and evidence rules below. There is no single tolerance number valid at every frequency and level; compliance requires the standard’s complete tests and the measurement method’s class requirement. This is an introductory excerpt, not the complete standard, a current compliance check or a project-specific calculation.
Choose the measured quantities, units, weighting and measurement basis before entering values. For a reference, select the exact topic. For a catalog lookup, prepare complete source-backed records; for a screen, select an applicable caller limit.
How to use IEC 61672 Class Reference and understand its results
- Choose the measured quantities, units, weighting and measurement basis before entering values. For a reference, select the exact topic. For a catalog lookup, prepare complete source-backed records; for a screen, select an applicable caller limit.
- Enter topic using the field table and calculation rules, then run the tool.
- Read source, statement, topic. 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 |
|---|---|---|---|
| topic | Reference topic to return. | string; one of "class-1", "class-2", "caution" | Required |
Choose one of the exact topic values in the table. The tool indexes a fixed, locally embedded reference entry and returns its source label, statement and unchanged topic. It does not fetch the source or update the wording. Topic meanings and all returned entries are shown below.
| Selection | Returned reference entry |
|---|---|
| class-1 | source: IEC 61672-1; statement: IEC 61672 Class 1 instruments have tighter tolerance limits and a wider specified frequency range than Class 2 instruments.; topic: class-1 |
| class-2 | source: IEC 61672-1; statement: Class 2 instruments support general-purpose measurements where the governing method permits their wider tolerances.; topic: class-2 |
| caution | source: IEC 61672 series; statement: There is no single tolerance number valid at every frequency and level; compliance requires the standard’s complete tests and the measurement method’s class requirement.; topic: caution |
selected exact topic → embedded source label, explanatory statement and topic Units, indexing, boundary conditions and exceptional cases are defined in the calculation rules above.
| Output field | Meaning | Value type |
|---|---|---|
| source | Source used for the reference statement. | string |
| statement | Narrow reference statement for the selected topic. | string |
| topic | Selected reference topic. | string; one of "class-1", "class-2", "caution" |
{
"input": {
"topic": "class-1"
},
"output": {
"source": "IEC 61672-1",
"statement": "IEC 61672 Class 1 instruments have tighter tolerance limits and a wider specified frequency range than Class 2 instruments.",
"topic": "class-1"
}
}Limitations and assumptions
There is no single tolerance number valid at every frequency and level; compliance requires the standard’s complete tests and the measurement method’s class requirement. This is an introductory excerpt, not the complete standard, a current compliance check or a project-specific calculation.
Numeric inputs, where present, must be finite. Follow the calculation-specific rules for overflow, underflow and exceptional cases. Extremely large text inputs are rejected. Missing fields without a declared default, extra fields, wrong value types and violations of the calculation rules are input errors.
Alternative or Complementary methods
Use Microphone Incidence Reference: A free-field microphone is designed so its presence and diffraction are compensated for sound arriving from the specified frontal direction. This reference explains the selected concept and the evidence needed to interpret it. For a complementary task, use Calibration Drift Screen: Before-and-after calibrator readings can reveal drift during a sound measurement session. An explicit acceptance allowance determines the screen.
References
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IEC 61672 Class Reference — tool.io
Similar or alternative tools
- Microphone Incidence Reference
A free-field microphone is designed so its presence and diffraction are compensated for sound arriving from the specified frontal direction. This reference explains the selected concept and the evidence needed to interpret it.
- Calibration Drift Screen
Before-and-after calibrator readings can reveal drift during a sound measurement session. An explicit acceptance allowance determines the screen.