The C9536-01/H9958 series are optical power meters designed to measure absolute optical power of UV light (mW/cm2). These optical power meters have a flat spectral response over a wide UV wavelength region, and are capable of measuring the optical power independent of the spectral emission distribution of a light source to be measured. Unlike commonly available UV power meters, optical power of various UV light sources can be easily measured with just one set of the C9536-01/H9958 series, without having to correct each wavelength of emitted light.