This workbook computes and displays the spectral blackbody emissive power for a number of source temperatures.  It allows the user to display the spectral blackbody emissive power for a particular temperature.  It also evaluates the integral over a wavelength range selected by the user (replicating the tabulated blackbody radiation functions). (See the cyan-colored lines in the figure below.) Another sheet is this workbook includes tabulated data for the spectral transmissivity of two types of glass.  One of them is standard glass, the other is a “low-E” (low-emissivity) glass. The student can use this function for blackbody emissive power, the tabulated glass data and Simpson’s Rule to find the total transmissivity of the two glasses.

Color Temperature

When you buy lightbulbs, whether LED, CFL or old-fashioned incandescent, you want to select a bulb that meets your needs.   For instance, you probably don’t want a “cool-white” light for in a sleeping room.   A recent addition to the HTTPlancksLaw Excel workbook allows you to see what the color of a blackbody would look like as a function of temperature.