Irradiance of a area per device frequency or wavelength. The terms spectral flux density or even more confusingly "spectral depth" can also be made use of. Non-SI models of spectral irradiance involve Jansky = 10 W⋅m⋅Hz and photo voltaic flux unit (1SFU = 10 W⋅m⋅Hz). The Dean of Devices https://russellp530irz7.signalwiki.com/user