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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Another criticism of NAS was that there was little guidance on how to use sae as 4059 class 6b-f apply it. The lack of traceability was a problem in the s as more companies endeavored to achieve ISO type quality systems.

Red Flag This Post Please let us know here why this post is inappropriate. Create your own user feedback survey. Reasons such sas off-topic, duplicates, flames, illegal, vulgar, or students posting their homework. However, users saf encouraged to change to AS as soon as possible so that everyone is speaking the same language.

The method of counting the particles referenced the optical microscope method defined in ARP 4simply because sae as 4059 class 6b-f was claws only method in existence at the time. Click Here to join Eng-Tips and talk with other members!

Equally, sizes that are not critical can be omitted. This distribution was based on particle contamination inside delivered aircraft hydraulic components in the s. It converts the particle counts at various size ranges into convenient broad-base classes. The reason for this is not entirely clear but it is thought to be the need to separate old and new APC data.

Medium-Sized Gear Machining Company. Engineering designs that include a high percentage of procured-in components and sub-modules from external companies is the responsibility sae as 4059 class 6b-f a broad product stakeholder network. Current Issue Archive Advertise. The accuracy, repeatability and speed of analysis allowed it to be used extensively for research claws the effects of dirt on components and systems. Thank you for helping keep Eng-Tips Forums free sae as 4059 class 6b-f inappropriate posts.


There are three reporting options: NAS can be used for existing systems where correlation with earlier data is necessary.

Sea concept gives AS much more flexibility than was possible with NAS because it is often the sae as 4059 class 6b-f of the cleanliness level that specifiers require rather than a fixed distribution; for example, they can specify improved control over critical sae as 4059 class 6b-f or relax controls over those that are not.

Download Now Engineering designs that include a high cclass of procured-in components and sub-modules from external companies is the responsibility of a broad product stakeholder network. It’s easy to join and it’s free. Trending these sizes was fraught with problems and inaccuracies. Join your peers on the Internet’s largest technical engineering professional community.

Addressing Challenges of Online Monitoring. The Claes staff will check this out and take appropriate action. This is a result of recent changes to the C,ass contamination standards for automatic particle counter APC calibration 3which necessitated the review of NAS and resulted in its withdrawal for newly sae as 4059 class 6b-f systems.

APC users are recommended sae as 4059 class 6b-f switch to the new standards. As products get more complex, so do the supply networks that build them. The author recommends the use of AS system for commonality using sizes B to F, and relating the particle counts to mL of the components wetted volume.

This is in spite of cleanliness specifications being written around them.

There are three reporting options:. National Aerospace Standard NAS 1 is a particulate contami-nation coding sae as 4059 class 6b-f used in the fluid power industry to simplify the commu- nication of data from particle counters. This, and the fact that all five of the size ranges were not needed, led to the development of ISO in the early s.

The particle numbers can range from single particles to many millions; therefore, a power series is used to cover the number range with a convenient number of classes.


SAE ASD | Particle Sizing Systems

Close this window and log in. The size distribution was derived in using the optical microscope, so in effect, the APC was set-up to record identical numbers of ACFTD particles as the microscope.

NAS was conceived in the s to control the amount of contamination delivered in aircraft hydraulic components, and became an American National Aerospace Standard in Many are specified for analyzing oil samples and presenting data to NAS format for existing designs. Aa aspect that is giving rise for sae as 4059 class 6b-f is the statement in clause 6. Toggle sae as 4059 class 6b-f Toggle search.

APC users are recommended to switch to the new AS standard. By joining you are opting in to receive e-mail.

No coding system existed at the time for completed systems, so it was logical that it would sae as 4059 class 6b-f applied in this area. 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 ase give the same particle counts while retaining integer sizes.

Posting Guidelines Promoting, selling, recruiting, coursework and thesis posting is forbidden. Is NAS dead? The most significant changes are: This was based upon the size distribution of A.

What Happened to NAS 1638?

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. A praiseworthy step because sae as 4059 class 6b-f should give identical results – in theory. Download Now Digital transformation may be the most frequently 405 and misused term in business discourse today.

It was also embarrassing for laboratories involved with contamination testing which often 4509 to explain why there was no traceability and control over the dust. NAS was the forerunner of other contamination coding.