Scanning Electron Microscopy for Technical Cleanliness

Cleanliness in the automotive industry is a key responsibility for manufacturers, where contamination control measures are now present at every stage of the automotive supply chain.

The ISO 16232 and VDA 19 are two cleanliness standards for automotive fluid systems, such as the brakes, hoses, nozzles, and pumps. Under the guidance of ISO 16232 and VDA 19, you can characterize and measure the particulate contamination of such parts.

In a previous blog post, we explained how an increasing number of manufacturers are using Scanning Electron Microscopes (SEMs) and energy dispersive spectroscopy (EDS) to determine the nature of contaminant particles based on their size, shape, and composition.

In this blog post, we explain the principles behind the international standard ISO 16232 and the German VDA 19 standard.

Automotive manufacturers must robustly inspect and analyze contamination to ensure product cleanliness. This is because contamination – including foreign particles and residues – can adhere to automotive components and parts during the manufacturing process, reducing the strength and safety of these products.

For example, the pistons in an automotive engine move constantly and are kept in an air-tight casing, with engine oil to aid their movement. If any metal contaminates adhere to the side surface of a piston ring, this could damage the inner wall of the cylinder liner, causing engine problems.

Ultimately, the effects of these contaminants can cause engines and other vehicle components to break, endangering human life. Because of this, cleanliness inspection and analysis are now indispensable steps in quality management for automotive manufacturers.

To help guarantee cleanliness, the ISO 16232 and VDA 19 cleanliness standards were introduced to the automotive industry in the early 2000s. These standards made the measurement and composition analysis of foreign particles and contaminants in compliance with their quality requirements mandatory across the industry.

They define the management of technical cleanliness for oil and water-related parts found in engines and transmissions, including pumps, tanks, valves, ducts, and pipes. They also outline the measurements and analyses to ensure that the technical cleanliness requirements defined in ISO 16232 and VDA 19 are satisfied. Both standards provide a set of general directives for contamination testing of fluid components in road vehicles and regulate the particle extraction methods and measuring equipment used.

In doing so, these standardized regulations create a mutual understanding between manufacturers and customers, helping automotive manufacturers guarantee the cleanliness of their vehicles.

The ISO 16232 and VDA 19 standards are closely related, both characterizing the cleanliness of products within the automotive industry. The ISO 16232:2018  (the latest version of the standard) supplies “requirements for applying and documenting methods for determining particulate contamination on functionally-relevant components and systems (cleanliness inspection) of road vehicles.”

The ISO 16232 was developed by the ISO (International Organization for Standardization), which is an independent, non-governmental international organization with members from 165 national standards bodies.

The ISO 16232 is based on the VDA 19 , which is a standard from The German Association of the Automotive Industry. The VDA 19 differs from the ISO 16232 “in the fact that the contents are more detailed” with additional examples included in the standard. The standard states the following subjects have been dealt with additionally or in more detail:

• Scope of application and validity
• Agreement on cleanliness inspection (informative)
• Simplified cleanliness inspection — monitoring variations (informative)
• Selection of inspection method (informative)
• Appropriate clean handling of test components
• Extraction procedure set up and validation and blank test
• Case examples

SEMs and EDS can determine the nature of contaminant particles, allowing users to comply with the ISO 16232 and VDA 19 industry standards. If you’d like to find out more about how our instruments can help you achieve compliance, or how to incorporate your own standards, click here to talk to a member of our team today.