In any hydraulic system, contamination influences the product life expectancy. The more contaminates present, the more wear the system receives, reducing the life of the system or parts of the system. To minimize the wear on the hydraulics due to particle contamination, machinists must not only monitor the system for wear during use, but must verify the cleanliness of any additives, such as hydraulic lubricants, to the system. While not even new lubricants are free of contamination, these lubricants must also have a high standard of cleanliness if the machinist wants to minimize the wear particles added from the lubricant.
The International Organization for Standardization (ISO) standard 4406 is a complied table of the number of acceptable particles of various sizes in a hydraulic system, which allows hydraulic filters to be rated according to what size particles they allow to pass through. Maintaining the correct filter helps ensure unwanted particles into the hydraulic fluid; however, simply replacing the filter and hydraulic fluid may not solve the contamination problem.
In order to comply with ISO 4406, machinists must be able to evaluate the number and size of the particles within their hydraulic system. To do this, Aspex has developed its Advanced Quality Control (AQC) software for its Personal Scanning Electron Microscope (PSEM), creating a totally integrated, automated inclusion analysis tool.
Not only can the AQC identify the presence of foreign particles, it can also identify the elemental composition of these foreign particles. With this knowledge, machinists can evaluate where the source of the contamination is, and adjust the quality control program if necessary. Due to the electron beam’s magnification range, depth of field, and powerful contrast mechanisms, it enjoys many performance advantages relative to the optical microscope for dimensional analysis of particles from the millimeter to the sub-micron range.
Automobile makers want to produce quality products, and in order to do that cleanliness must rise to such levels that systems can last significantly longer than they did in the past, due mainly to monitoring technology. The Aspex PSEM with AQC has proven to help maintain strict quality control guidelines. Aspex has provided the industry with its PSEM and AQC software, allowing manufacturers to monitor wear debris that would cause wear on hydraulic systems. While no system will be totally clean, cleanliness standards have reduced manufacturer and warranty failures by upwards of 30% for such hydraulic systems as transmission assemblies, power steering assemblies, fuel injection systems and diesel engines, making it a valuable asset for any manufacturer.
Reference:
Aspex, http://www.aspexcorp.com/industries/industrial-automation.html
Machine Lubrication, http://www.machinerylubrication.com/article_detail.asp?articleid=581
Contractors Unlimited, http://www.contractorsunlimited.co.uk/toolbox/hydraulicfluid.shtml
particle cleanlines standard