3.1 The color number variation of the oxidized oil samples
The fully formulated aviation lubrication oils, 928 and 50-1-4Φ, are applied in the oxidation reactions performs in the appliance shown in Figure 1. All of the comparative experiments of 928 and 50-1-4Φ aviation lubrication oils carried out in oil bath at the same time and temperature to produce a same oxidation condition in every single oxidation reaction. After oxidation reaction, the color evolution of the oxidized oil specimens is very clear in Figure 2.