This standard applies to the determination of the specific gravity of commercial grains and oilseeds. The specific gravity of grains and oilseeds is the ratio of the weight of the pure volume of grains and oilseeds to the weight of the same volume of water. GB/T 5518-1985 Grain and Oilseed Inspection Method for Determination of Grain Specific Gravity GB/T5518-1985 Standard Download Decompression Password: www.bzxz.net

National Standard of the People's Republic of China
Inspection of grain and oilseeds
Methods for determination of specific gravity of grain
Inspection of grain and oilseedsMethods for determination of specific gravity of grainGB/T5518-85
This standard applies to the determination of specific gravity of commercial grain and oilseeds. The specific gravity of grain and oilseeds is the ratio of the weight of the pure volume of grain and oilseeds to the weight of the same volume of water. 1 Graduated cylinder method
1.1 Apparatus and utensils
1.1.1 Graduated cylinder: 0.1ml scale;
1.1.2 Balance: sensitivity 0.01g.
1.2 Reagents
20% ethanol: 22ml of 95% ethanol plus 78ml of water. 1.3 Operation method
In a 20ml measuring cylinder, first inject 10ml of 20% ethanol, then put in 5g of the sample (W1), shake it slightly to expel the bubbles, and immediately read the volume of the liquid rise (V) after the liquid surface stabilizes. 1.4 Result calculationbZxz.net
The specific gravity of grain and oil (d) is calculated according to the following formula: W1
The weight of the sample, g;
W1—
W2—The weight of water of the same volume as the sample, g. W2=V·dwater. dwater is the density of water, approximately 1g/ml:YThe volume of the sample, ml.
2 Pycnometer method
2.1 Instrument
Pycnometer: A glass bottle with a long neck and a piston. There is a 1/10ml scale on the neck, which measures 10ml. The zero scale is at the bottom of the long neck and there is a piston under the zero position to adjust the liquid capacity. 2.2 Operation method
Inject 20% ethanol into the bottle and adjust the liquid level to zero using the piston. Then put 10g (W) of the sample into the bottle mouth, shake it slightly to expel the bubbles, and immediately read the scale (V) at the rising liquid level after laying it flat. 2.3 Calculation of results
The calculation of specific gravity d is the same as 1.4.
No double test is performed on the specific gravity of grain. The measurement result is taken to the second decimal place. Additional notes:
This standard was proposed by the Ministry of Commerce of the People's Republic of China. This standard was drafted by the Grain Storage and Transportation Bureau of the Ministry of Commerce. The main drafters of this standard are Gao Xiuwu, Yang Haoran, Wu Yanxia, ​​and Lv Guifen. Issued by the National Bureau of Standards on November 2, 1985
Implementation on July 1, 1986
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