Fig. 1. The selection device of SSC for fruit
Ⅰ: Detection; Ⅱ: Control; Ⅲ: Transfer;1: Trigger; 2: Step counter; 3: Gear; 4: Chain;5: Fiber; 6: Darkroom; 7: Halogen lamp; 8: Sample;9: Spectrometer; 10: PLC; 11: Sample cup;12: Trigger; 13: Graded export; 14: Motor

Fig. 2. Near-infrared diffuse transmission original spectra of watermelon

Fig. 3. Watermelon is divided into several regions for spectral collection and sugar content collection

Fig. 4. Location of soluble solids

Fig. 5. The content of soluble solids in watermelon varies with depth

Fig. 6. PLS model modeling scatter plot

Fig. 7. Number of principal component factors and root mean square error

Fig. 8. Regression coefficient diagram of watermelon soluble solids prediction model

Fig. 9. Schematic diagram of light transmitting inside watermelon