ISO 18, in the context of oil cleanliness testing, represents a range code that indicates the number of particles that are 4 microns and larger found in an oil sample. It is part of a three-number reporting system commonly used to express oil cleanliness levels.
Understanding the Three-Number System
Results from oil cleanliness tests are often reported using a three-number format, such as 18/16/13. Each number in this format corresponds to a different particle size:
- The first number (e.g., 18): Indicates the range of particles that are 4 microns and larger. In this example, ISO 18 represents this range.
- The second number (e.g., 16): Indicates the range of particles that are 6 microns and larger.
- The third number (e.g., 13): Indicates the range of particles that are 14 microns and larger.
How ISO 18 Works
When an oil sample is analyzed, the number of particles of various sizes is counted. The results are then categorized into ranges based on these sizes. Each range is assigned a code according to the ISO 4406 standard.
- The code number reflects a specific particle count range as per ISO 4406.
- The higher the number, the greater the number of particles within that size range.
- Therefore, an ISO 18 for particles 4 microns and larger indicates a certain quantity range within that specific parameter based on ISO 4406.
Practical Implications
The ISO cleanliness code provides vital information about the health and cleanliness of oil.
- Higher ISO codes indicate higher levels of contamination.
- Maintaining proper oil cleanliness is crucial for the performance and longevity of machinery.
- Contaminants can cause wear, tear, and premature failure of critical components.
- Regular oil analysis and proper filtration are essential for achieving the desired cleanliness level.
Example
Let's say an oil test returns a reading of 18/16/13. This means:
- The oil contains a certain range of particles that are 4 microns and larger, as indicated by the ISO 18 code.
- It also contains a specific range of particles that are 6 microns and larger, represented by ISO 16.
- Finally, there is a quantity within a specified range of particles 14 microns and larger, indicated by the ISO 13 code.
Conclusion
ISO 18 is not a measure of the size of particles, but rather, it's a code that represents a specific range of the number of particles that are 4 microns and larger in an oil sample according to the ISO 4406 standard.
