STANDARD PENETRATION TEST
STANDARD: BS 1377: PART 9:1990
This Standard sets out a method for determining the resistance of soils to the penetration of a sampler, and the obtaining of disturbed samples of the soils for identifi cation purposes. The Auto Trip Hammer, SPT Drive Rods and a Split Tube Sampler are worked together.
I. The Automatic Trip Hammer comprises a weight of 63.5 kg complete with pick-up and self-tripping
mechanism that ensures that the weight has a free-fall of exactly 760 mm. The inner shaft acts as a guide that permits the weight to drop with minimal resistance and ensures that the weight strikes the anvil squarely.
II. The SPT drive rods thread usually be processed with a 1.1/2" B.S. whitworth to fit our standard SPT rods. Adaptors to other types of drill rod can be supplied on request. The overall length of the hammer is 2.6m extended and 1.8 m when unextended. The total weight of the hammer is 107 kg.
III. The standard Split Tube Sampler is 2" (50.8 mm) OD x 1-3/8" (34.9 mm ) ID x 18" (457 mm) / 24" (610 mm) long. For heavy driving conditions, the Heavy-duty "Tufl ok" design is available.