GB/T 5491-2025Inspection of grain and oil seeds - Sampling and dividing (English PDF)

5.1.1 Manual sampler for packaged grains

5.1.1.1 Single-tube sampler for large grains Approximately 75 cm in total length, with a probe length of approximately 55 cm and a mouth width of

1.8 cm. The top is pointed or duckbill-shaped, with an outer diameter of

2.2 cm. Suitable for sampling large grains such as corn and soybeans; see B.1.

5.1.1.2 Single-tube sampler for small and medium-sized grains Approximately 70 cm in total length, with a probe length of approximately 45 cm, a mouth width of approximately 1 cm. The top is pointed, with an outer diameter of approximately

1.5 cm. Suitable for sampling small and medium-sized grains such as wheat, paddy rice, rice, millet, mung beans, red beans, and rapeseed; see B.1.

5.1.1.3 Single-tube sampler for powdered grains Approximately 55 cm in total length, with a probe length of approximately 35 cm, a mouth width of approximately

0.6 cm ~

0.7 cm. The top is pointed, with an outer diameter of approximately 1 cm. Suitable for sampling powdered grains such as wheat flour and corn flour; see B.1.

5.1.2 Manual samplers for bulk grains

5.1.2.1 Thin-walled sleeve sampler Available in three total lengths. 1 m, 2 m, and 4 m. It has three inlet holes, each approximately 15 cm long and

1.5 cm wide at the opening, with a top length of approximately 7 cm and an outer diameter of approximately

2.2 cm. Suitable for sampling bulk grains such as wheat and paddy rice; see B.2.1.

5.1.2.2 Thick-walled sleeve sampler Available in three total lengths. 1 m, 2 m, and 4 m. It has three inlet holes, each approximately 15 cm long and

1.8 cm wide at the opening, with a top length of approximately 7 cm and an outer diameter of approximately

2.8 cm. Suitable for sampling bulk grains such as corn and soybeans; see B.2.1.

5.1.2.3 Ellis cup sampler Made of lightweight aluminum, used for sampling from a grain stream running on a conveyor belt; see C.4.

5.1.2.4 Sampling shovel It is mainly used for sampling or bag dumping sampling of mobile grains and oil seeds, and extra-large grains and oil seeds.

5.2 Electric sampler

5.2.1 Fixed automatic grain sampler It is composed of a sampling rod, rotating arm, moving device, column, grain conveying pipe, negative pressure vacuum system, and electrical control system, etc. It is mainly used for automatic sampling of packaged or bulk grains in uncovered transport vehicles; the sampling port of the sampling rod shall be able to reach any position of the grain on the vehicle; see B.2.2.

5.2.2 Mobile electric suction grain sampler It is composed of a multi-hole end tube, sampling head, connector, sampling tube, discharge gate, storage box, vacuum chamber, hose, etc. It is designed and manufactured based on the negative pressure principle; and shall meet the requirements for deep bulk grain sampling; see B.2.3. When sampling by using this type of sampler, if the impurity content of the sample is greater than 1.0%, and relevant parties raise objections to the test results, the sampler described in

5.2.3 shall be used to resample and test the impurity content, or the relevant parties shall negotiate and confirm the requirements for correcting the impurity content test results.

5.2.3 Mobile electric bulk grain sampler It is composed of a motor, a negative pressure vacuum system, a handle, a grain suction port, a sampling connecting rod (outer tube), and a connecting sampling bucket (inner tube), etc. It shall comply with the provisions of LS/T 3547; see B.2.4.

5.2.4 Mobile electric suction packaged grain sampler It is composed of a machine head, filter screen, buffer sample collector, handle, sample dispensing port, sample connecting rod, sample receiving cup, and grain suction port, etc. It shall comply with the provisions of LS/T 3548; see B.2.5.

5.3 Sample divider It includes sample dividing plates, bell-shaped sample dividers, Riffle sample dividers, Canadian-style sample dividers, automatic sample dividers, etc.; see Appendix D.

5.4 Sample dividing cloth or padding The sample dividing cloth can be a thicker plastic sheet or other fabric. The padding material can be a smooth, flat wooden board or glass plate, etc.

5.5 Sample containers The commonly used containers include sample tubes, sample bags, sample bottles, etc.

6.1 Representative quantity of inspection units

6.1.1 Bulk grains and oil seeds Generally, an inspection unit is defined as no more than 500 tons. For large ships, an inspection unit is defined as no more than 1,000 tons. For large flat warehouses and round silos, an inspection unit is defined as no more than 2,000 tons (this may be increased by no more than 15% if necessary, depending on the actual storage quantity). For extra-large grains and oil seeds (peanuts, peanut kernels, sunflower seeds, castor seeds, broad beans, sweet potato chips, etc.), an inspection unit is generally defined as no more than 100 tons.

6.1.2 Packaged grains and oil seeds Generally, an inspection unit is defined as no more than 500 tons.

6.1.3 Inspection lot An inspection lot may have one or more inspection units. For lots exceeding those specified in

6.1.1 and 6.1.2, the number of inspection units shall be increased accordingly. For round silos exceeding 2,000 tons, generally increase by no more than four inspection units. The inspection results for the entire silo or entire cargo location can be expressed as a weighted average of the inspection data from all inspection units when all inspection units meet the requirements.

6.2 Sampling type Based on the state of the grain or oil seed, sampling is divided into static sampling and dynamic sampling. Bulk grains and oil seeds can use either static or dynamic sampling, while packaged grains and oil seeds can use static sampling.

6.3.1 Sampling of bulk grain and oil seeds by vehicles, ships, and warehouses

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