Exam Question

Modern Analysis Techniques for Lubricating Oil Condition Analysis
(a) Elemental (Spectrometric) Analysis
Elemental analysis is used to determine the concentrations of 15-25 different elements, ranging from wear metals and contamination to oil additives. This technique operates on the principle of Atomic Emission Spectroscopy (AES) .
In AES, individual atoms within a sample are excited using a high-energy source. These atoms absorb energy and transition to a higher electronic state. Due to quantum physics, excited atoms rapidly release this gained energy, primarily by emitting light. The frequency (and thus wavelength) of the emitted light is characteristic of the atom's electronic structure. By measuring the amount of light emitted at specific wavelengths for elements like Iron, Copper, Zinc, and Sodium, their concentrations can be determined. The unit of measurement is parts per million (PPM) .