Please Note: You are viewing the unstyled version of POLARIS Laboratories. Either your browser does not support CSS (Cascading Style Sheets) or it is disabled. As a result, much of this website will not look the way it was intended, although all of its contents will be accessible to you. For more information, visit our Browser Support page.

Skip to Primary Site Navigation, Secondary Site Navigation, Content, Company Address

Home > Publications Directory > Technical Bulletins > Decoding the ISO Cleanliness Code

Decoding the ISO Cleanliness Code

Fluid cleanliness is critical to establishing equipment reliability and there is a direct correlation between oil cleanliness and component life.

When a wear condition advances, the size and concentration of wear particles in the oil increases. The best method for measuring particle size and concentration is particle count testing. Results are reported in particles per milliliter or particles per 100 milliliters (depending on the lab) at a given size (microns) and ISO Cleanliness Code. The ISO Cleanliness Code was developed for measuring fluid cleanliness and is widely used for determining particle counts in lubricants. It specifies the size of particles measured and the method for coding the level of contamination.

The ISO 4406 standard utilizes a three number system to classify system cleanliness — example: 19/16/13. The first number means there are between 2,500 and 5,000 particles >4 μm, between 320 and 640 particles >6 μm and between 40 and 80 particles >14 μm. The second represents particles greater than 6μm and the third represents those greater than 14μm. Consider the particle count data shown in Table 1 below. Use the ISO range codes in Table 2 to determine the system's ISO Cleanliness Code.

Table 1
Size Particles / mL
4μ 2852
6μ 541
10μ 198
14μ 56
21μ 11
38μ 1
70μ 0
100μ 0

Table 2

ISO/Range Code Min. particles /mL Max particles /mL
1 0 0.02
2 0.02 0.04
3 0.04 0.08
4 0.08 0.15
5 0.15 0.3
6 0.3 0.6
7 0.6 1.3
8 1.3 2.5
9 2.5 5
10 5 10
11 10 20
12 20 40
13 40 80
14 80 160
15 160 320
16 320 640
17 640 1,300
18 1,300 2,500
19 2,500 5,000
20 5,000 10,000
21 10,000 20,000
22 20,000 40,000
23 40,000 80,000
24 80,000 160,000
25 160,000 320,000
26 320,000 640,000
27 640,000 1,300,000
28 1,300,000 2,500,000
29 2,500,000 5,000,000
30 5,000,000 10,000,000

The ISO Cleanliness Code for the test data shown in Table 1 would be 19/16/13. Because the number of 4μm particles is between 2,500 and 5,000, the corresponding ISO code is 19. Because the number of 6μm particles is between 320 and 640, the corresponding ISO code is 16. Because the number of 14μm particles is between 40 and 80, the corresponding ISO code is 13.

Work with the OEM, your lubricant and filter suppliers and your oil analysis laboratory to determine acceptable ISO cleanliness code limits for machinery by application.

Print this Technical Bulletin (PDF - 142K)


Top

News

POLARIS Laboratories™ to provide fluid analysis for AES Defence Early Failure Detection Centre

POLARIS Laboratories™, an innovative leader in fluid analysis services in North America, announced today their partnership with UK-based AES Defence who provides oil analysis services for more than 1,500 British military vehicles.

Read More

Sign Up for eNewsletters


Training

  • Salt Lake City
    Practicing Oil Analysis
    March 30-31, 2010

  • Houston
    Practicing Oil Analysis
    June 22-23, 2010

  • Indianapolis
    Cooling Systems Maintenance
    July 20, 2010

View complete schedule and registration information


Tradeshows & Conferences

  • Truck World
    Toronto, ON
    April 15-17, 2010

  • CIM
    Vancouver, Canada
    May 9-12, 2010

View all tradeshows