... . SAT-F5 Optical Multimeter is handheld and intelligent multi-function measurement instrument integrating with LD source and optical power range module, ... continuous light and all functions of SAT-4E seriesoptical power meter, and the wavelength of light source :650nm ,850nm ... 0.03dB/15min ; ±0.05dB/8h Wavelength of optical power meternm850,980,1300,1310,1490,1550,1625Measurement rangedBm-70~+ ...