Channel sampling is a technique used by geologists to collect small chips of rock over a specified linear interval. The objective is to cut a linear channel across the vein or orebody for the most representative samples possible over the designated interval. Channel sampling is important because it allows for a representative sample to be acquired, which is not biased.
Channel samples are typically collected in succession along a sample line that is laid out in advance using a measuring tape. The sample line is designed to cross the area of interest. Channel samples can be collected along surface trenches, floors or walls of underground workings.
Sample intervals are set at a specified width, usually ranging from 1 to 20 feet, commonly 5 feet. This allows for a representative sample to be acquired as the sample is not biased. Channel sampling is an important technique used by geologists, especially in Ontario, Canada.