ISO 4406 Standards for Particle Counting
Application Note 6 - ISO 4406 Standards for Particle Counting
Number of particles per millilitre |
Scale number | |
| More Than | Up to and Including | |
| 80,000 | 160,000 | 24 |
| 40,000 | 80,000 | 23 |
| 20,000 | 40,000 | 22 |
| 10,000 | 20,000 | 21 |
| 5,000 | 10,000 | 20 |
| 2,500 | 5,000 | 19 |
| 1,300 | 2,500 | 18 |
| 640 | 1,300 | 17 |
| 320 | 640 | 16 |
| 160 | 320 | 15 |
| 80 | 160 | 14 |
| 40 | 80 | 13 |
| 20 | 40 | 12 |
| 10 | 20 | 11 |
| 5 | 10 | 10 |
| 2.5 | 5 | 9 |
| 1.3 | 2.5 | 8 |
| 0.64 | 1.3 | 7 |
| 0.32 | 0.64 | 6 |
| 0.16 | 0.32 | 5 |
| 0.08 | 0.16 | 4 |
| 0.04 | 0.08 | 3 |
| 0.02 | 0.04 | 2 |
| 0.01 | 0.02 | 1 |
| 0.005 | 0.01 | 0 |
| 0.0025 | 0.005 | 00 |
The ISO 4406 code specifies either two or three size ranges. The scale number refers to the number of particles per 1 ml in each size range. The scale numbers are reported with a backslash between them, with the >5 (or >2) micron scale number always first.
See the Examples Below:
2 Code Particle Count |
3 Code Particle Count |
|||||
| Size | Count | Scale | Size | Count | Scale | |
| >5 | 3620 | 19 | >2 | 11893 | 21 | |
| >15 | 28 | 12 | >5 | 3620 | 19 | |
| >15 | 28 | 12 | ||||
| ISO Code = 19/12 | ISO Code = 21/19/12 | |||||