The netting in composed by meshes in different dimensions and 3 different shapes: Diamond, Square and Hexagonal.
The side drawing shows the different mesh definitions.
There is another method in which is calculated the lenght of 10 consecutive meshes, than dividing by 10 and the result is the avarage half mesh dimension.
When the meshes are used in diamond shape the confection procedures use the mesh opening with E=0,71, as the wider mesh dimension possible and 90° angles. This number has to be multiplied by the mesh size dimension in order to determine the “fmg” size.
There are several mesh measure in the world. In the below table are mentioned the most commons.
Conversions: hmkk= 200/P = 1260/On = 119/Os = 183/R = 200/N-1 = 30/F-1 A simple method of measuring stretched mesh size is as follows: extend a panel of twine fully in Diamond shape direction and measure the distance between the centre of 2 knots separated by 10 meshes. Then divide this measure by 10. * Data from "Fisherman Handbook" - FAO - 1990