Fig. 1. Diagram of system structure

Fig. 2. Flow chart of terminal node and gateway communication process

Fig. 3. Flow chart of sending and receiving data of the gateway

Fig. 4. Schematic diagram of the internal principle of SiPM

Fig. 5. Physical drawing of JSP-TP6050-SMT

Fig. 6. Relationship between photon wavelength and detection efficiency

Fig. 7. KTY83/110 resistance change with temperature

Fig. 8. Temperature-compensated power supply circuit diagram

Fig. 9. Spectral curve of NaI energy resolution test

Fig. 10. Detection efficiency curve of NaI detextor

Fig. 11. Schematic diagram of relay node

Fig. 12. Signal strength comparison of node network access

Fig. 13. Relationship between counting rate and dose rate

Fig. 14. Display interface of the upper-computer centralized monitoring platform