A constant appearing in the Planck radiation formula; its value depends on the form of the formula used; in the formula for power emitted by a blackbody per unit area per unit wavelength interval, it is 2π times Planck's constant, times the square of the speed of light, or approximately 3.74177 × 10-16 watt (meter)2. Symbolized c1; C1.
first radiation constant can be classified under Physico-Chemical Constants.
Value 3.741 771 53 x 10-16 W m2
Standard uncertainty 0.000 000 17 x 10-16 W m2
Relative standard uncertainty 4.4 x 10-8
Concise form 3.741 771 53(17) x 10-16 W m2