Automated multiple location sampling analysis system
An analysis system (e.g., LIBS) includes a laser source generating a laser beam, a movable optic configured to move said laser beam to multiple locations on a sample, and a spectrometer responsive to photons emitted by the sample at those locations and having an output. A controller is responsive to a trigger signal and is configured in a moving spot cycle to adjust the moveable optic, activate the laser source sequentially generating photons at multiple locations on the sample, and process the spectrometer output at each location.
1. An analysis method comprising:
adjusting a moveable optic in a moving spot cycle;
activating a laser source emitting a beam striking the moveable optic creating a plasma generating photons at multiple locations on a sample;
analyzing the photons at each location; and
automatically terminating the moving spot cycle if the analysis of the photons indicates the sample is homogeneous.
2. The method of claim 1 in which the moving spot cycle is also automatically terminated when a predetermined maximum number of sample locations have been analyzed if analysis of the photons after said predetermined maximum number of sample locations have been analyzed fails to indicate the sample is homogenous.
3. The method of claim 1 in which analysis of the photons indicates the sample is homogenous when multiple concentration levels at multiple locations deviate by less than a predetermined percentage.
4. The method of claim 3 in which multiple concentration levels at multiple locations deviate by less than a predetermined percentage when the standard deviation of a mean concentration is less than a predetermined threshold.
5. The method of claim 1 in which the movable optic includes an adjustable focusing lens.
6. The method of claim 1 in which the movable optic includes one or more mirrors or a glass optic.
7. The method of claim 1 in which the laser source is activated generating a series of laser pulses at each location.
8. The method of claim 1 further including adjusting the focus of the beam.
9. The method of claim 8 in which adjusting the focus of the beam is based on the analysis of plasma generated photons at each location.
10. The method of claim 9 in which the focus of the beam is adjusted until a maximum or near maximum intensity is reached for at least one spectral intensity peak of the plasma generated photons.
11. The method of claim 1 is further including initiating a cleaning cycle at each location and terminating the cleaning cycle at each location.
12. The method of claim 11 in which the cleaning cycle is terminated at each location based on the analysis of plasma generated photons at each location.
13. The method of claim 12 including analyzing the intensity of one or more spectral intensity peaks of the plasma generated photons for multiple pulses at each location.
14. The method of claim 13 in which terminating the cleaning cycle occurs when said intensity changes by less than a predetermined percentage over a predetermined number of laser pulses.
15. The method of claim 14 in which analyzing the intensity includes computing a rolling average of the intensity over multiple pulses.
16. An analysis method comprising:
adjusting a moveable optic in a moving spot cycle;
activating a laser source emitting a beam striking the moveable optic creating a plasma generating photons at multiple locations on a sample;
analyzing the photons at each location; and
automatically terminating the moving spot cycle, based on the analysis of the photons, when multiple concentration levels at multiple locations deviate by less than a predetermined percentage.
17. The method of claim 16 in which the moving spot cycle is also automatically terminated when a predetermined maximum number of sample locations have been analyzed.
18. The method of claim 16 in which the analysis includes determining the standard deviation of a mean or average concentration.
19. The method of claim 16 in which the movable optic includes an adjustable focusing lens.
20. The method of claim 16 in which the movable optic includes one or more mirrors or a glass optic.
21. The method of claim 16 in which the laser source is activated generating a series of laser pulses at each location.
22. The method of claim 16 further including adjusting the focus of the beam.
23. The method of claim 22 in which adjusting the focus of the beam is based on the analysis of plasma generated photons at each location.
24. The method of claim 23 in which the focus of the beam is adjusted until a maximum or near maximum intensity is reached for at least one spectral intensity peak of the plasma generated photons.
25. The method of claim 16 is further including initiating a cleaning cycle at each location and terminating the cleaning cycle at each location.
26. The method of claim 25 in which the cleaning cycle is terminated at each location based on the analysis of plasma generated photons at each location.
27. The method of claim 26 including analyzing the intensity of one or more spectral intensity peaks of the plasma generated photons for multiple pulses at each location.
28. The method of claim 27 in which terminating the cleaning cycle occurs when said intensity changes by less than a predetermined percentage over a predetermined number of laser pulses.
29. The method of claim 28 in which analyzing the intensity includes computing a rolling average of the intensity over multiple pulses.