A Turnkey Solution to Technical Cleanliness
Image analysis software systems make cleanliness analysis efficient and economical
Ensuring the cleanliness of fluids and finely machined parts is important for a range of industries including automotive, aerospace, rail, and hydraulics. The use of parts contaminated by even the smallest particle can lead to costly failures and reduce the overall use-life of products. Consequently, cleanliness analysis is an essential part of the quality control process. Today’s newest image analysis software systems have been designed to make cleanliness analysis efficient and economical, providing significant advantages over manual optical counting methods and making it easy to ensure that all international standards (such as ISO 16323 and ISO 4404) are met.
Manual optical particle counting has been around for a long time, but concerns over accuracy and reproducibility have led to the development of automated solutions in the way of image analysis software. Manual counting systems typically rely on a stereo microscope. Operators scan the filter membranes, and particles are measured using a scale in the eyepiece. This method is tedious and error-prone since operators are dependent on grid lines printed on the filter to assist with scanning. Because each grid must be manually inspected, it’s easy for an operator to lose their place and skip sections of the filter. Since each operator is doing all of the scanning and particle measuring by hand, this introduces a range of potential errors. Of particular concern is an operator’s ability to accurately measure the maximum Feret diameter, or the maximum distance between two parallel tangential lines of each particle, and to measure it reproducibly. These data sets are important since they are required to meet national and international standards. Manual counting also doesn’t leave a permanent record of the data potentially creating a need for repeat testing.
Residue particles collected and filtered onto a filter membrane.
Image analysis software systems, such as the OLYMPUS CIX100 cleanliness inspector, are intuitive metrological tools that automatically locate, count, and measure particle size while providing report-quality images and metrics. The user sets the minimum particle size that the system detects by setting a threshold. Once this is established, the rest of the process is fully automated, enabling employees to engage in other tasks while the system does all of the work. A filter is placed on the motorized microscope stage, and the unit scans and images the entire filter in as little as a few minutes. The Feret diameter of each particle that it encounters ranges from 2.5 microns to several millimeters in size. The software applies the same standard of measurement to each particle, thus eliminating the variability that is introduced when a human operator is manually taking measurements.
Software systems, like the CIX100 cleanliness inspector, offer advantages over other kinds of automatic particle size counters. Some, such as laser optical particle counting, are cost-prohibitive, prone to false positives, and provide no visual image. Others, such as SEM, are expensive, time-consuming, and require extensive sample preparation. Today’s newest image analysis software, however, is cost-effective and requires minimal training to use. Its sophisticated measurement technology provides a quantitative validation of component cleanliness that can be used in professional reporting. When each scan is completed, the software system automatically generates an easy-to-read particle size distribution and classification report with statistical information and a complete photographic sample map for easy viewing. An automatic classification feature can organize particles into categories, or bins, after it measures them. The size of each bin is based on whatever standard the company is using. This enables the user to easily view the distribution of particles by size. A go-back-to-particle function enables the user to quickly return to any particle detected by the unit for immediate validation, and a revision mode enables the user to easily separate, delete, and draw particles, or perform a complete re-classification.
The cleanliness of fluids and machined parts directly impacts the overall reliability, quality, and use-life of products. The right image analysis software system can provide a single-source solution for cleanliness analysis and fluid cleanliness results that are reproducible and reliable—a comprehensive fail-safe system for detection, visualization, identification, and reporting.