Source: https://guthlabs.ai/docs/instruments/electric-potential-point-charges-calculator/implementation/

instrument implementation / implementation-contract

# Electric Potential (Point Charges) Calculator implementation

A source-bound implementation contract for Electric Potential (Point Charges) Calculator; deployment and executable qualification remain separate.

Status: **VERIFIED_CLEAN**Lifecycle: **implementation-contract**

## Binding contract

This record describes what an executable surface must bind and validate. It does not claim that a public calculator, package, or production route is deployed.

**Record owner**: Guth Instruments

**Lifecycle**: verified-clean

**Evidence ID**: t5-180

**Effect**: Computation or source lookup only

## Input and validation requirements

The formula has an undefined zero-distance case, so the instrument must reject r=0 rather than perform plain division. The specification also leaves distance-sign conventions unstated and has no actual piecewise formula branch.

## Required corrections

No binding erratum is attached to this unique-name record. Implementers must still preserve the declared units, domain, and failure behavior.

## Inspectable interface fixture

The sample below is evidence for interface and validation tests, not a production implementation.

````
{
  "inputs": {
    "k_N_m2_per_C2": 8990000000,
    "q_C": 0.000002,
    "r_m": 0.3,
    "q1_C": 0.000002,
    "q2_C": -0.000003,
    "pair_distance_m": 0.5
  },
  "expected_outputs": {
    "V_V": 59933.333333333336,
    "U_J": -0.10788
  },
  "working": "V=(8.99×10^9)(2×10^-6)/0.30=(17980)/0.30=59933.333333333336 V. U=(8.99×10^9)(2×10^-6)(-3×10^-6)/0.50=(8.99×10^9)(-6×10^-12)/0.50=(-0.05394)/0.50=-0.10788 J."
}
````

## Other records

[01**Overview**](<https://guthlabs.ai/docs/instruments/electric-potential-point-charges-calculator/>)[02**Mechanism**](<https://guthlabs.ai/docs/instruments/electric-potential-point-charges-calculator/mechanism/>)[04**Qualification**](<https://guthlabs.ai/docs/instruments/electric-potential-point-charges-calculator/qualification/>)

## Sources and evidence

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

- `VERIFIED_LEDGER.json`

- `evidence-tranche5/tranche5-results.json`