In most cases, a mix-up test on steel workpieces is carried out by determining the material identity by means of a spectrometer. There are both stationary and portable operating spectrometers for this purpose, in which the air emission spectrum of the workpiece sparked on the untreated surface is compared with the spectrum of a reference sample.
Of course, we also have employees with level 2 certification who are available for a visual inspection (VT).

The carbon content of the workpiece can only be determined very inaccurately or not at all spectroscopically, so that a further procedure for carbon determination is required. Usually, the visual grinding spark test is used for this purpose in operation. The actual chemical analysis of the approximately 10 mm long reference piece is usually determined either wet-chemically or in the laboratory using a vacuum emission spectrometer.

 This method is not one hundred percent meaningful, since the grinding spark test is a subjective test and the error rate is still very high for material grades with only slight differences in carbon content due to the limited perceptive capacity of the human eye.