Fuel and Lubricant Testing


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NAS 1638 - Aerospace Hydraulic Fluid Cleanliness Standard

We perform hydraulic fluid quality testing by FTM 3012 to determine whether aerospace hydraulic fluids meet the NAS 1638 cleanliness standard. NAS 1638 is not a test method, but is a cleanliness standard for hydraulic fluids used in aviation applications.  It is widely used in industrial and aerospace applications.

The particle count is determined using manual or automated methods (FTM 3012).

The NAS 1638 classification is the "worst case" code across the particle size ranges.  For example, a sample with 1,500 particles in the 5-15 μm range and 50 particles in the 15-25 μm range would be a Class 3.

Contact us today to receive a quote for your hydraulic fluid testing.

Sample quantity required: 300 ml

We also perform particulate contamination testing by Hach 8160FTM 3012, ISO 4406FTM 3010FTM 3009ASTM D6217ASTM D5452ASTM D4176ASTM D2276FTM 3013ASTM D4898. These different test methods use different instruments or procedures or are used for certain sample types. Click on the test method number to learn more about each test.