![]() “4” as the Contamination Level for H-I means 8-16 particles in the 200µm-600µm size range were found (if on a report) or are allowed per 1,000cm 2 if it is a Standard Area based Limit being displayed (on the print or in a table.) “H-I” means that size classes H (200µm-400µm), and I (400µm-600µm) are combined so that particles from 200µm-600µm essentially make up a size class named “H-I.” “10” as the Contamination Level for F-G means 500-1,000 particles in the 100µm-200µm size range were found (if on a report) or are allowed per 1,000cm 2 if it is a Standard Area based Limit being displayed (on the print or in a table.) “F-G” means that size classes F (100µm-150µm), and G (150µm-200µm) are combined so that particles from 150µm-200µm essentially make up a size class named “F-G.” If a Contamination Level of “15” is displayed as your Standard Area based Limit then it means up to 32,000 particles are allowed per 1,000cm 2. A Contamination Level of “15” on an Area based report means there are 16,000 – 32,000 particles in that size class in the Standard Area of 1,000cm 2. “15” = Contamination Level = number of particles allowed for the size class preceding the Contamination Level number. “C-E” means that size classes C (15µm-25µm), D (25µm-50µm), and E (50µm-100µm) are combined so that particles from 15µm-100µm essentially make up a size class named “C-E.” The most common ISO 16232 cleanliness codes display Standard Area based spec Limits designated by the “A” in front of the parentheses. “A” = Area = Standard Area = 1,000cm 2 (defining cleanliness per a Standard Area allows you to directly compare cleanliness of parts of differing sizes) It could have either a “V” for volume or a “N” for numbers of particles per part instead of an “A” for Standard Area. So what does that ISO 16232 cleanliness code mean? Then the inspection procedure can be documented as the sum of the extraction processes required to verify effectiveness.So what does that strange code CCC = A(C-E15/F-G10/H-I4/J-K00) mean? You do some research and discover the cleanliness limits listed on the print or in a table are an ISO 16232 cleanliness code which is totally based on particle count rather than mass. Verification is complete when the measurement for a given iteration is less than 10 percent of the sum. The measurement taken at each iteration is then divided by the sum of the measurements leading to that step (see Figure 1). This process is repeated on the same set of test components for as many as six total iterations. The extracted contamination then must be measured and documented. One set of test components is subjected to a process intended to extract particulate contamination. The verification process is almost identical in both industry standards. ![]() ![]() Verifying effectiveness ensures that the extraction procedure is removing at least 90 percent of the contamination from the tested components. The effectiveness of the extraction procedure must be verified. ![]() They ensure an effective extraction procedure, an adequate number of components and a compatible test liquid.ġ. ![]() To help answer that question, let’s consider three of the 300 requirements established by ISO 16232 and VDA 19 that are covered in this article and examine whether customer-specific standards comply with them. ![]()
0 Comments
Leave a Reply. |