Thermal conductivity is typically measured using a device called a thermal conductivity meter. This device measures the amount of heat that passes through a material over a specific period of time, and calculates the thermal conductivity based on this measurement.
The most commonly used unit for measuring thermal conductivity is watts per meter-kelvin (W/mK). However, other units such as BTU per hour-square foot-degree Fahrenheit (BTU/hr-ft2-°F) are also sometimes used.
Some of the main factors that can affect thermal conductivity measurements include temperature, humidity, and the composition and density of the material being measured. Other environmental factors, such as air flow and pressure, can also have an impact.
Thermal conductivity can be measured for most solid and liquid materials. However, it may not be possible to accurately measure the thermal conductivity of materials that are very thin, highly porous, or have a low thermal conductivity.
In some cases, it is possible to calculate the thermal conductivity of a material using known values for other properties, such as density and specific heat. However, these calculations may not be as accurate as direct measurements and can be affected by variations in material composition and environmental factors.