split-barrel sampler . A steel tool for sampling soil that is driven into the formation. The split barrel is held together by a bit at one end and a head at the other. The bit and head are removed to permit separation of the two sides of the split barrel to expose the sampled soil. Samplers commonly have core catchers made of plastic or steel that are located between the bit and the split barrel. Cf: penetration test. Syn: split-spoon sampler.