Using Atomic Spectrometry and Volumetry Method for Determination of Bearing Corrosion in Tribotechnical Diagnostics of Engines

The presence of water in the engine lubrication system is supposed to be a significant factor, which causes engine corrosion. Atomic spectrometry method and method for water content determination were applied for the detection of corrosion. Rotating disc electrode optical emission spectrometry (RD OES) is a method used to determine the concentration of 21 chemical elements in used lubricating oil in 30 seconds. In the used oil the concentration of Fe, Cu and Sn was monitored because these elements are indicators of bearing wear. The elements were analyzed using Conostan S-21 organo metallic calibration standards. The precision of the method was verified by calculating RSD for n = 3, the values of which are for Fe, Cu and Sn less than 7 %. Accuracy of measurement was verified by measuring standard reference material NIST 1084a. Karl Fischer volumetric method was used for the determination of water content in used lubricating oils with precision less than 1 %. The obtained reference material 34849 HYDRANAL-Water Standard 10.0, which is traceable to NIST SRM 2890 for determination of water content by Karl Fischer method, was analyzed for accuracy purposes.