The figures are differential counts, and the NAS class is usually reported as a single figure >5µm. >15µm. >25µm. >50µm. >µm. Size code. A. B. C. D. E. F. 76 SAE AS rev E Table Particle Contamination Level by Class. The SAE aerospace standard (AS) ASD defines cleanliness classes for particulate contamination of hydraulic fluids and includes methods of reporting. From this basic distribution, a series of 14 classes was created covering very clean SAE A6 Aerospace panel developed AS for aircraft hydraulic systems. . instance NAS Class 6, can be swapped to AS Class 6B through F.
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The reason for this is not entirely clear but it is thought to be the need 6-f separate old and new APC data. Machine Oil Case Study: Engineering designs that include a high percentage of procured-in components sae as 4059 class 6b-f sub-modules from external companies is the responsibility of a broad product stakeholder network.
The reasoning behind this is not entirely clear, but thought to be to separate old and new APC data.
What Happened to NAS 1638?
Trending these sizes was fraught with problems and inaccuracies. Close this window and log in.
Few aircraft companies adopted this standard, and very few industrial companies even knew it existed despite the fact that it overcame the deficiencies of NAS The method of counting the particles referenced the optical sae as 4059 class 6b-f method defined in ARP 4simply because this was the only method in existence at the time. The introduction of the APC during the s revolutionized the measurement of the size distribution of dirt particles saw a hydraulic system.
The author considers AS to be a significant advance over NAS because it offers many benefits. The most significant changes are: Medium-Sized Gear Machining Sa. Equally, sizes that are not critical can be omitted.
NAS saw widespread acceptance in the s and s by industries where reliability was a prerequisite, in areas such as offshore oil production, iron and steel industries, etc. The lack of traceability was a problem in the s as more companies endeavored to achieve ISO type quality systems. The accuracy, repeatability and speed of analysis allowed it to be used extensively for research into the effects sae as 4059 class 6b-f dirt on components and systems.
Red Flag This Post Please let us know here why this post is inappropriate. Many are specified for analyzing oil sae as 4059 class 6b-f and presenting data to NAS format for existing designs. It was also claass for laboratories involved with contamination testing which often had to explain why there was no traceability and control over the dust.
sae as 4059 class 6b-f If you obtain the latest issue of NAS you will find the following statements: Oklahoma State University, under the direction of Prof. This subsequently became de facto ISO Thank you for helping keep Eng-Tips Forums free from inappropriate posts. Addressing Challenges of Online Monitoring. This concept gives AS much more flexibility than was possible with NAS because it is often the control of sae as 4059 class 6b-f cleanliness level that specifiers require rather than a fixed distribution; for example, they can specify improved control over critical sizes or relax controls over those that are not.
In Table 3 it can be seen that the particle counts are defined by a number relating to the quantity of particles and a letter relating to the size. Because this situation could cause an uproar within the industry when companies would have to change specifications, the ISO committee decided to take the road of least resistance and selected new size descriptors that would give the same particle counts while retaining integer sizes.
APC users are recommended to switch to the new AS standard.
Create your own user feedback survey. Sae as 4059 class 6b-f basis of the code is seen in Table 3. No coding system existed at the time for completed systems, so it was logical that it would be applied in this area.
This, and the fact that all five ssae the size ranges were not needed, led to the development of ISO in the early s. This distribution was based on particle contamination inside delivered aircraft hydraulic components in the s.
SAE AS equivalent ISO/DIN – SAE (Automotive) Code Issues – Eng-Tips
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