The GDS950 Glow Discharge Spectrometer delivers advanced technology for routine elemental analysis and compositional depth profiling of both electrically conductive and non-conductive solid materials. By combining robust hardware with intuitive Cornerstone® software, the GDS950 simplifies operation, reporting, and data handling while reducing overall analysis time in the laboratory.
LECO: GDS950 Extended Range Glow Discharge Atomic Emission Spectrometer
LECO: GDS950 Extended Range Glow Discharge Atomic Emission Spectrometer
The GDS950 is well suited for bulk elemental determination in metals and other solid materials such as steel, cast iron, titanium, and related alloys. With the optional CDP capability, the system supports depth profile analysis of surface treatments including galvanizing, plating, heat treatment layers, and claddings. When equipped with the optional DC/RF lamp configuration, the analytical scope expands to include electrically non-conductive materials such as paints, glass, plastics, and other coated or polymeric solids.
Glow Discharge Spectrometry (GDS) is a direct analytical technique for determining the elemental composition of solid samples. A flat, prepared sample is mounted on the glow discharge source, which is evacuated and then backfilled with argon gas. An electric field is applied between the sample, acting as the cathode, and the grounded lamp body, serving as the anode, resulting in a stable, self-sustained glow discharge plasma.
The applied current is controlled by the power supply, while lamp voltage is stabilized through regulation of the argon pressure. Once the plasma is formed, argon ions are accelerated toward the sample surface. Through cathodic sputtering, kinetic energy is transferred to surface atoms, ejecting them into the plasma.
Models equipped with the optional radio frequency (RF) source use RF energy instead of direct current to sustain the plasma. LECO’s proprietary True Plasma Power algorithm compensates for radiated and reflected power losses, enabling accurate quantitative bulk analysis and depth profiling of both conductive and non-conductive samples.
Ejected atoms undergo inelastic collisions with energetic electrons or metastable argon atoms, becoming electronically excited. As these atoms return to lower energy states, they emit photons at wavelengths characteristic of each element. Because every element has a unique emission spectrum, elemental identification is achieved through spectrochemical signatures.
The emitted light is collected by a spectrometer whose optical system is continuously purged with argon to maintain transparency across the ultraviolet and visible range. CCD detector arrays capture the full spectrum from 120 to 460 nm simultaneously. The resulting signals are digitized and processed to remove dark current, normalize pixel response, extend dynamic range, and eliminate pixel artifacts. Quantitative results are obtained by calibrating against reference materials of known composition.
