ELECTRONICS · REFERENCE GUIDE
Temperature sensors (PT/NI/CU, NTC, thermocouples)
Reference guide to temperature sensors (PT/NI/CU, NTC, thermocouples): the checks to work through, the limits that apply and when to verify against the NEC.
US (NEC) only · NFPA 70 / NEC — locally adopted editionDefaults are US values. Verify the locally adopted NEC edition and project data.Official reference ↗
REFERENCE GUIDE
Before starting
- Choose exact sensor type and calibration standard before converting.
- PT/NI/CU require material coefficients and reference resistance; NTC needs B or Steinhart–Hart constants.
- Thermocouples require type-specific polynomials and cold-junction compensation.
- The cable temperature calculator provides only a simple linear resistance relation.
This is a reference guide, not a sizing calculator or installation approval.
Method & assumptions
Reference workflow — project-specific verified data required
This is a reference guide, not a sizing calculator or installation approval.
Results do not check every aspect of an electrical installation. The calculators follow US (NEC) practice only; a regional preset changes defaults such as voltage and units, and no result certifies NEC compliance.
Sources and validation →Estimating and invoicing tool
Ampxa is developing an estimating and invoicing application for electrical contractors. The list below receives notice when it opens.