One fix wavelength given by chosen interference filter in range 200-600 mn. Interference filter determining wavelength is ordered separately.
For VIS range (350-900 nm) with LED diode as light source.
Small unit measured at wavelength 254 nm
For 254 nm with build in recorder
Manual wavelength setting 190 up to 600 nm
Programmable, 190 up to 600 nm , informative scan