Fig. 1. Optical structure diagram of remote LIBS system

Fig. 2. The best D₁, D₂ at different working distances

Fig. 3. DOF at 5 m working distance

Fig. 4. The Variation of DOF with working distance

Fig. 5. LIBS spectra at different working distances

Fig. 6. Variation of spectral line intensity with working distance

Fig. 7. Focal spot at 2 m (a), 4 m (b), 6 m (c), 8 m (d)

Fig. 8. The relationship between focal spot diameter and working distance

Fig. 9. The standard curves of Ni (a, b), Cr (c, d), Nb (e, f), Mo (g, h), Ti (h, i) and Al (j, k)

Fig. 10. The relationship between LIBS test result error and test times