What is cold junction compensation in thermocouples?
Cold junction compensation accounts for the temperature at the reference junction where thermocouple wires connect to measurement equipment. Since thermocouple voltage depends on temperature difference, the cold junction temperature must be known for accurate measurements. See also our calculate Output Voltage, Bridge Sensitivity & Signal-to-Noise Ratio — Strain Gauge.
Which thermocouple type should I choose?
Type K is most common for general purpose (-200°C to 1260°C), Type J for industrial applications, Type T for low temperatures, Type E for high sensitivity, Type B for high temperatures, and Type N for improved stability over Type K.
What is the Seebeck coefficient?
The Seebeck coefficient (dV/dT) represents the thermocouple's sensitivity at a specific temperature, showing how much voltage changes per degree of temperature change. Higher values indicate greater sensitivity.
Why are thermocouple voltages measured in millivolts?
Thermocouples generate very small voltages, typically in the millivolt range. For example, a Type K thermocouple produces about 41 microvolts per degree Celsius, so measurements are expressed in millivolts for practical precision.
How accurate are NIST thermocouple tables?
NIST thermocouple reference tables are highly accurate, typically within ±0.1°C for most thermocouple types. These tables are the international standard for thermocouple calibration and temperature conversion.
Can I convert between different temperature units?
Yes, this calculator supports Celsius (°C), Fahrenheit (°F), and Kelvin (K) temperature units. The thermocouple voltage relationships remain consistent regardless of the temperature scale used for display.