ISO 21945:2020

1) fine (up to about 10 mm nominal top size) and regularly-shaped particulate materials that can be sampled using a scoop or pipe, e.g. sawdust, olive stones and wood pellets;

2) coarse or irregularly-shaped particulate materials (up to 200 mm nominal top size) that can be sampled using a fork or shovel, e.g. wood chips, hog fuel and nut shells;

3) large pieces (above 200 mm nominal top size) which are picked manually (e.g. firewood and briquettes).

This document can also be used for other solid biofuels not listed above if the procedures described in this document are applicable. This document specifies methods to be used, for example, when a sample is to be tested for moisture content, ash content, calorific value, bulk density, mechanical durability, particle size distribution, ash melting behaviour and chemical composition.

Additionally, it describes a method for the reduction of sample size and defines requirements on handling and storage of samples.

NOTE 1 If higher precision of analytical results is needed or when in doubt if this document is applicable ISO 18135 can be used. Using the number of increments given in this document the resulting precision for analytical results can be estimated with the formulas given in ISO 18135.

NOTE 2 Pellets can generate CO and CO₂ off gasses by nature. If pellets are sampled, check for CO and CO₂ and O₂ levels prior and during the sample taking process in a confined space like a container, silo or shed and have another person standby at the entrance.