GB 5491-1985 English PDF (GB5491-1985)

Delivery: 3 seconds. Download true-PDF + Invoice.
Get QUOTATION in 1-minute: Click GB 5491-1985
Historical versions: GB 5491-1985
Preview True-PDF (Reload/Scroll if blank)

GB 5491-1985: [GB/T 5491-1985] Inspection of grain and oilseeds. Methods for sampling and sample reduction
GB 5491-1985
GB
NATIONAL STANDARD OF THE
PEOPLE’S REPUBLIC OF CHINA
UDC (633.1+633.85)
001.4
GB/T 5491-85
Inspection of grain and oilseeds - Methods for
sampling and sample reduction
ISSUED ON: NOVEMBER 02, 1985
IMPLEMENTED ON: JULY 01, 1986
Issued by: National Bureau of Standards
Table of Contents
1 Sampling tools ... 3 
2 Sampling methods ... 4 
3 Sample reduction methods ... 6 
Additional information: ... 7 
Inspection of grain and oilseeds - Methods for
sampling and sample reduction
This Standard applies to the quality inspection of grains and oilseeds.
1 Sampling tools
1.1 Sampler: also known as grain probe. There are two types: packaging and
bulk packaging.
1.1.1 Packaging sampler: three types.
1.1.1 Packaging sampler: three types.
1.1.1.1 Large grain sampler: the overlength is 75cm; the probe length is 55cm;
the mouth width is 1.5~1.8cm; the head is pointed or duckbill; the maximum
outer diameter is 1.7~2.2cm.
1.1.1.2 Medium and small grain sampler: the overlength is 70cm; the probe
length is 45cm; the mouth width is about 1cm; the head is pointed; the maximum
outer diameter is about 1.5cm.
1.1.1.3 Powdered grain sampler: the overlength is about 55cm; the probe length
is about 35cm; the mouth width is 0.6~0.7cm; the head is pointed; the maximum
outer diameter is about 1cm.
1.1.2 Bulk packaging sampler: three types.
1.1.2.1 Thin tube sampler: the overlength is 1m or 2m; with three holes, each
hole mouth length is about 15cm; the mouth width is about 1.5cm; the head
length is about 7cm; the outer diameter is about 2.2cm.
1.1.2.2 Thick tube sampler: the overlength is 1m or 2m; with three holes, each
hole mouth length is about 15cm; the mouth width is about 1.8cm; the head
length is about 7cm; the outer diameter is about 2.8cm.
1.1.2.3 Electric suction sampler (inapplicable to impurity inspection).
1.2 Sampling shovel: mainly used for sampling of flowing grain, oilseeds or
upside-down sampling.
diameter of the round warehouse is less than 8m, each layer sets 1, 2, 4 points,
7 points in total, according to the inner, middle and outer circles. When the
diameter is more than 8m, each layer sets 1, 4, 8 points, 13 points in total,
according to the inner, middle and outer circles. Conduct sampling according to
layers and points.
2.3 Packaging sampling method
2.3.1 The number of sampling packages of medium and small grains and
oilseeds shall not be less than 5% of the total number of packages. The number
of wheat flour sampling packages is not less than 3% of the total number of
packages. The package points of sampling shall be evenly distributed.
When sampling, use the packaging sampler, with notch down, to insert the other
end of the package diagonally from one end of the package. Then put the notch
upwards and take it out. The number of samplings per packaging is the same.
2.3.2 Sampling packets of extra-large grains and oilseeds (such as peanuts,
kernels, sunflower seeds, castor beans, broad beans, sweet potato chips): Not
less than 10 packages when it is less than 200 packages. When it is more than
200 packages, for every additional 100 packages, increase 1 package.
When sampling, take the upside-down packaging and unpacking method.
Sampling ratio: For upside-down packaging, it is 20% of the number of sampling
packages specified. For unpacking: it is 80% of the number of sampling
packages specified.
Upside-down packaging: Put the sampling package on a clean plastic sheet or
the ground first. Remove the stitches. Put it down slowly. Hold the two corners
of the bottom of the package tightly with both hands. Lift it to about 50cm height.
Drag down about 1.5m and pour out all. Use the sampling shovel to take the
samples out from the middle and the bottom of the package. The number of
samples per package and each point is consistent.
Unpacking: Disconnect 3~5 stitches at the package mouth. Use the sampling
shovel to take the required samples from the upper part. The number of
samples per package is consistent.
2.4 Flowing grain sampling method
Sampling of mechanically conveyed grain and oilseeds: According to the
quantity of inspected grain and oilseeds and the delivery time, determine the
number of samplings and the quantity to be taken each time. Then periodically
take samples from the end of the grain flow.
2.5 Sampling method of sporadic receipt and payment of grain and oilseeds