Remote LIBS System Enables Process Control Under Challenging Environmental Conditions

LTB Lasertechnik Berlin introduces its new Remote LIBS system for non-contact process control from a greater distance. In industrial manufacturing, it is increasingly necessary to measure remotely from a safe distance due to complex process conditions (temperature, humidity, required protective measures, process speed). The Remote LIBS system allows plasma generation on a sample from a distance of several meters and the detection of its spectral emission. The spatial resolution is less than 1 mm. The imaging system is also suitable for other measurement methods.

Remote LIBS thus offers a wide range of applications for material analysis and process control, such as in the production and characterization of steel, aluminum, glass, ceramics, and concrete, as well as in geology, environmental analytics, and safety technology.

The Remote LIBS system is based on the echelle spectrometers of the ARYELLE and ARYELLE-Butterfly series, developed by LTB in collaboration with the Institute for Analytical Sciences (ISAS) Berlin, for simultaneous elemental analysis using laser-induced plasma spectroscopy (LIBS). The ARYELLE spectrometer concept allows the detection of elements in the wavelength range from 175 nm to 750 nm with a resolution of 35,000 in the VUV range and 15,000 in the UV-VIS-NIR range.

The spectrographs can be variably dimensioned in terms of component parameters, such as entry slit, echelle grating, prism, and imaging optics. LTB Lasertechnik Berlin offers the spectrometers with both CCD and ICCD cameras. The use of a CCD in combination with a chopper provides better line sampling compared to an ICCD detector due to the better spatial resolution and quantum efficiency of the detector. Compared to ICCD, a factor of about 10 better signal-to-noise ratio is achieved through lower intrinsic noise and at a lower device cost. The advantages of the ICCD include higher temporal resolution and greater variability in control.

The control and analysis software Sophi for ARYELLE, developed by LTB for the ARYELLE series, controls all spectrometer and detector functions. After the calculation of the three-dimensional image data into wavelength-dependent intensity values, all spectral lines are automatically analyzed using an integrated spectral table and assigned to the corresponding elements. Quantitative analysis algorithms are also integrated. For quantitative measurement, calibration with comparable reference materials is necessary.

Various lasers are used for plasma excitation, such as Nd:YAG, excimer lasers, as well as LTB’s low-divergent nitrogen laser MNL 100-LD.