Radiant Flux

Radiant Flux (Φ) is energy per unit time (dQ/dt) that is radiated from a source over optical wavelengths, which are defined to be from 3x10¹¹ and 3x10¹⁶ Hz. This range is approximately equivalent to wavelengths from .01 to 1000 μm and includes the regions of the electromagnetic spectrum commonly referred to as Ultra Violet (UV), Visible, and Infra Red (IR).

辐射通量（Φ）是单位时间内（dQ/dt）从源辐射出的能，该辐射覆盖光学波长，光学波长定义为从3×10¹¹到3×10¹⁶ Hz。这一范围大约相当于从0.01到1000 μm的波长，包括电磁谱中通常称为紫外（UV）、可见光和红外（IR）的区域。

The flux is measured in units of Joules per second (J/s), or Watts (W). A radiant flux of 1 W means that a source produces 1 Joule every second. If we integrate radiant flux over time we obtain the total Energy (Q) output by the source.

辐射通量的单位是焦耳每秒（J/s），或瓦特（W）。1瓦特的辐射通量表示源每秒产生1焦耳的能量。如果我们对辐射通量进行时间积分，就得到源输出的总能量（Q）。

Most of the time when we deal with light sources, we do not really need to qualify optical radiation. For instance, if we look at the standard incandescent lamp, we know that the flux output below .01 μm is negligible, and that there is also very little energy output in the microwave and radio regions of the EM spectrum. So we can reasonably assume that the Flux output for a standard lamp is restricted to be in the optical range, and in doing so we may take the nominal wattage as our radiant flux. That is, a 60 W incandescent lamp would have a radiant flux of 60 W, and a 250 W Mercury vapor lamp would have a radiant flux of 250 W.

大多数情况下，当我们处理光源时，我们并不需要特别说明光学辐射。例如，如果我们考虑标准的白炽灯，我们知道在0.01 μm以下的波段输出是微不足道的，而且在电磁波谱的微波和无线电区域也有非常少的能量输出。因此，我们可以合理地假设标准灯的辐射输出主要限制在光学范围内，在此情况下，我们可以将额定瓦数作为辐射通量。也就是说，一个60瓦的白炽灯会有60瓦的辐射通量，而一个250瓦的汞灯会有250瓦的辐射通量。