| 摘要 |
<p>A method and apparatus for in-process transient spectroscopic analysis of a molten metal, wherein a probe (10) containing a pulsed high-power laser (14) producing a pulsed laser beam having a substantially triangular pulse waveshape is immersed in the molten metal and irradiates a representative quantity of the molten metal. The pulsed laser beam vaporizes a portion of the molten metal to produce a plasma plume having an elemental composition representative of the elemental composition of the molten metal. Before the plasma plume reaches thermal equilibrium shortly after termination of the laser pulse, a spectroscopic detector (241) in the probe (10) detects spectral line reversals, during a short first time window. Thereafter, when the afterglow plasma is in thermal equilibrium, a second spectroscopic detector (242) also in the probe (10) performs a second short time duration spectroscopic measurement. A rangefinder (22) measures and controls the distance between the molten metal surface and the pulsed laser (14).</p> |
