Decibel (dB) Converter

Inspectable records

Ledger state

The current ledger marks this instrument verified clean within the source-bound verification corpus.

Area

Electrical & Electronics Engineering — Circuits, Power Systems, Electronics Lab

Tranche

tranche-3

Evidence ID

t3-018

Ledger rows

1

No ledger note is attached.

Review findings

The formulas are standard in their properly constrained domains, but the specification is ambiguous about operation selection, units, RMS versus peak voltage, impedance assumptions, and inverse conversions. The empty honest_label also fails to disclose the equal-impedance and milliwatt-reference requirements.

Formula and scope findings

• dB=10log10(P2/P1) is correct for power ratios, provided P1 and P2 are positive and expressed in the same units.
• dB=20log10(V2/V1) is correct for voltage or amplitude ratios, provided V1 and V2 use the same quantity type and units; interpreting it as a power-equivalent dB value additionally requires equal impedances.
• dBm=10log10(P_mW) is correct only when P_mW is the numerical power value measured in milliwatts, because dBm is referenced to 1 mW. If power is supplied in watts, the formula must be 10log10(P_W/0.001 W).
• The claimed bidirectional dBm ↔ watts conversion is incomplete: the inverse formula P_W=0.001×10^(dBm/10) is not specified.
• The claimed bidirectional ratio or dB conversion is incomplete: inverse formulas such as P2/P1=10^(dB/10) and V2/V1=10^(dB/20) are not specified.

Unit assumptions

• P1 and P2 are positive powers in identical units, so their ratio is dimensionless.
• V1 and V2 are positive voltage or amplitude magnitudes in identical units, with the same RMS/peak convention.
• A voltage-ratio dB result is treated as power-equivalent only when the compared voltages are across equal impedances.
• P_mW means the numerical power in milliwatts, not a value in watts.
• For dBm-to-watts conversion, 0 dBm equals 1 mW = 0.001 W.

Boundary hardening

BREAK_CLAIMED · SELF_FLAGGED

A zero reference produces an undefined ratio and must be rejected. The specification also leaves ratio direction and power-versus-voltage branch selection implicit, allowing sign errors or a factor-of-two conversion error.

Errata and corrections

No applied erratum is attached to this unique-name record.

Inspectable example

4 review vectors are recorded. One source-bound sample is shown below.

{
  "inputs": {
    "mode": "power_ratio_to_db",
    "P2": 100,
    "P1": 1,
    "power_unit": "mW"
  },
  "expected_outputs": {
    "dB": 20
  },
  "working": "P2/P1 = 100/1 = 100. dB = 10×log10(100) = 10×2 = 20 dB."
}

Related workflows

No source-defined multi-instrument workflow membership is recorded.

Sources and evidence

These pointers bind the page to evidence. They do not grant authority or collapse verification into deployment.

• VERIFIED_LEDGER.json · VERIFIED_CLEAN
• evidence-tranche3/tranche3-results.json
• BOUNDARY_HAZARD_CATALOG.json