| OELCHECK test instrument: | Metrohm Robotic Titrosampler 855 |
| Sample quantity: | 20 ml |
| Unit: | mgKOH/g |
| Test result: | NN (neutralisation number) |
| Result range: | 0.01 - 99 mg KOH/g |
| Analysis for: | all industry oils e.g. from hydraulics, gears, heat transfer systems, oil circulation systems, transformer oils, landfill gas engines |
| Brief description: | The neutralisation number (NN) indicates the amount of potassium hydroxide required to neutralise the acids contained in a gram of oil. At the neutralisation number, an indicator is added to a mixture of oil and solvent which will indicate the neutral state during titration through a colour change. |
| Statement: | By comparison with the fresh oil values, the NN allows conclusions to be drawn regarding the oxidation of the oil and the breakdown of oil additives. It provides essential supplementary information for the extension of oil change intervals. |
| Underlying test standard: | DIN ISO 6618, ASTM D974 |
| Comparable methods: | ASTM D664: potentiometric determination of the acid number ASTM D8045: AN determined for petroleum and petroleum products using a thermometer |
