Customizing a 780 system for Automotive Parts Contamination
Single Particle Optical Sizing (SPOS) has been used to measure particle contamination in liquids, both pharmaceutical and industrial, for decades. For example, the Accusizer 780 SIS system was specially designed for measuring particle contamination in injectable pharmaceutical liquids following the test procedure detailed in USP-788.
In addition to liquids, there are a variety of devices, like valves, medical implants, and electrical switches where proper operation can be effected by the presence of particles that are residual of the manufacturing process. In order to reduce the failure rate of these sensitive devices, manufacturers are setting cleanliness specifications for these parts and for secondary parts that are used in conjunction with them. The difficulty comes with actually characterizing the particles in a device which may have a complex internal surface like a valve or hose. The way such particles are detected is to flush or wash the part with a clean liquid which can then be analyzed using the SPOS technique.
How to wash or flush the part can be a variable in the measurement. The number of particles counted will be a function of the time and type of liquid exposure. A wash procedure is chosen based on a vigorous method development. So it is likely that flush/wash procedures will vary with the type of part. That means that cleanliness systems will have to be customized for a given application.
Particle Sizing Systems has developed for a customer an innovative 780 system to perform cleanliness testing on hoses used in the automotive industry. The hoses themselves are not particle sensitive but the liquid that flows through them will carry existing particles into a pump which is particle sensitive. So the hoses must be clean too. Furthermore, it was stipulated in the cleanliness specification that the hoses be washed in a fashion similar to the liquid flow that exists in the sub-system that the hose is used in. This means that the hoses must be flushed at high flow rates, much higher than the flow rates used for SPOS systems. So the system, pictured below, had to contain two flow paths, one to wash the parts at high flow rates and one to flow the wash fluid through the SPOS sensor. Software had to be developed to operate both flow paths in addition to added steps needed to perform the actual measurement (allowing the test liquid to de-gas for example).
This customized 780 system is an example of Particle Sizing Systems ability to deliver unique particle sizing solutions for our customers.
The front and back of the customized 780 system for hose cleanliness tester. The front side contains the flush loop and the measurement loop. The back side contains a filtration system to enable re-use of the wash liquid.