Analysis of Carbon Contents and Heavy Metals in Coal Samples Using Calibration-free LIBS Technique

Table 1

Plasma temperature and electron number densities of the coal samples.

Coal samples	Temperature (K)	Electron number density (cm^-3) (×10^17)
Chinese	8300 ± 400	2.84 ± 0.8
Lakhra	8500 ± 600	3.01 ± 0.7
Duki	8200 ± 500	2.33 ± 0.9
Makerwal	8800 ± 600	2.41 ± 0.7
Thar	7900 ± 500	2.17 ± 0.6