Fig. 1. System architecture of NIR spectral sensing IoT

Fig. 2. Architecture of 256×1 spectral sensor integrated 64 channels filter

Fig. 3. Spectral sensor integrated LVF. (a) Architecture of the spectral sensor; (b) spectral channels of 256×1 spectral sensor; (c) spectral channels of 512×2 spectral sensor

Fig. 4. Assembly structure of LVF spectral sensor

Fig. 5. Corresponding relations between wavelength and spectral channels of three spectral sensors

Fig. 6. Normalized spectral response of three spectral sensors.(a) Spectral sensor integrated 64 channels filter; (b) 256×1 LVF spectral sensor;(c) 512×2 LVF spectral sensor

Fig. 7. Typical data path of spectral sensing IoT

Fig. 8. Practical application demonstration pictures of spectral sensing IoT. (a) Spectrum of low pressure mercury lamp tested by spectral sensing node; (b) test spectrum obtained by mobile phone client at a specific time