Table 6.
WHO hole size guidelines and hole index used to assess physical integrity of LLINs
| WHO 2013 guidelines | Size banding | Hole diameter | Hole radius | Area of hole | Hole Indexa | |
|---|---|---|---|---|---|---|
| cm | d; cm | r = d/2; cm | r2; cm2 | cm2 | ||
|
Size 1 Smaller than a thumb |
0.5–2 | 1.25 | 0.625 | 0.3906 | 1.23 | 1 |
|
Size 2 Larger than a thumb but smaller than a fist |
2.5–10 | 6 | 3 | 9 | 28.28 | 23 |
|
Size 3 Larger than a fist but smaller than a head |
11–25 | 17.5 | 8.75 | 76.5625 | 240.56 | 196 |
|
Size 4 Larger than a head |
≥ 26 | 30b | 15 | 225 | 706.95 | 576 |
A -area of the hole pr2; p = 3.142; a Area divided by 1.23; b Assumed diameter