Optical emission spectroscopy using arc and spark excitation (Arc Spark OES) is the preferred method for trace metal analysis to determine the chemical composition of metallic samples. This process is widely used in the metal making industries, including primary producers, foundries, die casters and manufacturing.
Optical emission spectrometry involves applying electrical energy in the form of spark generated between an electrode and a metal sample, whereby the vaporized atoms are brought to a high energy state within a so-called "discharge plasma".
These excited atoms and ions in the discharge plasma create a unique emission spectrum specific to each element, as shown at right. Thus, a single element generates numerous characteristic emission spectral lines.
INFORMATION. Rockwell hardness test, a differential-depth method, the residual depth of the indent made by the indenter is measured. The deeper a defined indenter penetrates at a defined test force into the surface of a workpiece (specimen), the softer the tested material. In the Rockwell method, the total test force is applied in two stages. This allows the impact of specimen surface roughness (e.g. grooves in the specimen) and measuring errors caused by backlash in indentation depth measurement to be eliminated. THE INDIVIDUAL ROCKWELL METHODS ARE DISTINGUISHED FROM EACH OTHER AND. The five resulting Rockwell methods use five different indenters (diamond cone with 120 o curvature or a hard metal ball made from tungsten carbide with diameters of: 1/16",1/8",1/4",1/2") and six different total test forces (15, 30, 45, 60, 100, 150 kgf).. This results in 30 different - standardised according to ISO 6508 and ASTM E18 – Rockwell scales (e.g. A, B, C, 30N, ...
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