split spoon sampler
1980 Edition

IS 9640 specifies precise dimensions and allowable tolerances for split spoon sampler parts as depicted in Figures 1 to 4 and 6. These include overall assembly length, component fitting measurements, cutting shoe specifications with square threads for coupling, split body internal and external diameters, liner dimensions for composite samplers, and coupling thread sizes. All measurements are provided in millimeters, ensuring proper assembly and function, particularly for threaded connections and split body halves. Composite samplers with liners are excluded from N-value determination in SPT. For detailed numerical data, the standard’s figures should be consulted.

IS 9640 encompasses standard split spoon samplers and heavy-duty variants. The standard sampler, approximately 450 mm in length with a 50 mm outer diameter, is designed for soft to medium soils and consists of mild steel with a longitudinal split for sample retrieval. The heavy-duty sampler, featuring thicker walls and increased weight, is intended for denser or harder soils requiring higher driving forces. The differences lie primarily in wall thickness, weight, and suitability for soil conditions, ensuring appropriate selection based on ground characteristics.

Yes, IS 9640 permits the use of liners inside split spoon samplers, creating what is termed a composite sampler. These liners, generally made of smooth brass pipe, facilitate the retrieval of relatively undisturbed soil samples, especially for laboratory analyses requiring minimal disturbance. However, composite samplers with liners are not to be used for determining Standard Penetration Test N-values, as the liner interferes with penetration resistance measurements.

While IS 9640 does not explicitly mandate marking procedures, best practices suggest that samplers should be clearly marked with the manufacturer's name or trademark, serial or batch numbers for traceability, dimensional details (such as diameter and length), material grade, and references to compliance with standards like IS 9640:1980. Markings should be permanent and corrosion-resistant, typically achieved through engraving or stamping, ensuring clear identification and certification traceability during usage and quality control.

No, composite samplers equipped with liners are explicitly not recommended for obtaining N-values in Standard Penetration Tests. According to IS 9640, the presence of a liner affects the accuracy of penetration resistance readings, rendering N-value measurements unreliable. The standard split spoon sampler without a liner must be used for accurate N-value determination.