The copper corrosion test is a test that evaluates the corrosion potential of mineral oils against copper and copper alloys. This test is especially important for detecting the presence of sulfur, acids or other corrosive substances in the oil. Since some parts of machinery and equipment are made of copper or copper alloys, this test gives an idea of whether the oil will damage these parts.

**Common Test Method:**
- **ASTM D130:** This standard test method involves leaving a copper strip in oil for a specified time and temperature, and then assessing the extent of corrosion.

**Test Administration:**
1. A copper strip is cut to a specific size and purity and pre-cleaned.
2. This copper strip is placed in the oil sample to be tested.
3. The oil is heated at a certain temperature for a certain time (for example, 3 hours at 100°C).
4. When the heating process is complete, the copper strip is removed from the oil and visually inspected for any signs of corrosion or discoloration.
5. The results are evaluated by comparing them with a scale indicating the degree of corrosion.

The copper corrosion test is used to evaluate how well the oil neutralizes corrosive substances or its potential to corrode. High degrees of corrosion may indicate that the oil is contaminated or that some special additive is missing. This test provides valuable information on the quality and performance of the oil and is used in conjunction with other tests to determine appropriate maintenance or oil change requirements.