The influence of sample preparation quality on the results of spectral analysis

Abstract

Сonsiders the possibility of analyzing samples of small diameters without the use of special adapters for determining the chemical composition on spectrometers. Measurements are limited to the size of the hole on the analytical table, which is 12 mm. Accordingly, all analyzed samples must have a diameter of at least 14 mm to completely cover the sample cover of the discharge chamber in order to avoid air entering the chamber. The company manufacturer of spectral equipment offers to use special adapters for the analysis of small samples. But the use of such adapters has a number of drawbacks. These include additional cash costs for the purchase of adapters, the need for additional standardization procedures, the availability of special reference samples. In the laboratory of analytical support (LAS) of the Central Laboratory of the Factory (CLF), all samples of finished rolled products (wire rods or fittings) in size from 5.5 mm to 20 mm are prepared in the form of «blades». The compressed part of the «blade» is the analyzed surface of the sample, which is further processed on a disk grinder and transmitted to the spectral analysis. The article presents the results of comparative tests of valves class U500 between samples in the form of «blades» and in the form of «columns» and concluded that the necessity of use of special adapters.

Keywords

• sample preparation
• chemical composition
• spectral analysis
• optical emission spectrometer
• small diameter rolling
• adapter