GB 7848-1987 Determination of forest soil firmness GB7848-1987 standard download decompression password: www.bzxz.net

National Standard of the People's Republic of China
Determination of forest soil consistence
Determination of forest soil consistence This standard applies to the determination of soil consistence. This standard adopts the consistence meter method.
1 Key points of the method
UDC 634.0.114
GB 7843-87
When the probe of the durometer (soil consistence meter) is pressed into the soil, the spring proportional to the resistance of the probe is also compressed accordingly, and the probe is also pressed into the durometer accordingly. The pressure required to press the probe is proportional to the hardness of the soil. 2 Main instruments
Soil consistence meter (with spring cursor), with various types of springs and probes. 3 Determination steps
3.1 First, determine the soil's solidity so as to select the appropriate thickness of the spring and probe type. For soft soil, use 16mm cylindrical probe; for medium-hard soil, use 10mm cylindrical probe; for hard soil, use 22.17mm conical probe and thick spring. 3.2 Before working, the cursor indicator line of the sleeve should point to 5cm, or to the "0" kg pressure borne by the volume of the probe. 3.3 During operation, the instrument should be perpendicular to the soil surface (or the wall of the pit). When the probe is withdrawn into the soil until the retaining plate touches the soil surface, the number of centimeters (i.e. the depth of the probe in the soil) can be read from the position where the cursor indicator line is aligned. 3.4 According to the depth of the probe in the soil, the type of probe, and the thickness of the spring, the value of the soil firmness can be calculated. Or check the "Soil Firmness Conversion Table" (Table 1, Table 2, Table 3). Table 1 Soil solidity conversion table (10mm cylindrical probe) Solidity,
kef/cm?
Depth,
Approved by the National Bureau of Standards on June 4, 1987
Implementation on January 1, 1988
Solidity
kgf/cm3
Deep soil depth
Solidity
kgf/cm3
Deep soil depth
Result calculation
GB 7843--87
Table 2 Soil compactness conversion table (Φ16mm cylindrical probe) 0
Soil firmness conversion table (§22.7mm conical probe) Table 3
190291.2623300.91
95145.63/11650.49
Soil firmness is inversely proportional to the volume of the probe and directly proportional to the pressure it bears. 0.5
1398.06|791.08486.85|318.57
243.43159.28
6990.03395.54
Where: AP-
GB 7843-87
Yuan r2dbzxz.net
-Soil firmness, kgf/mm2,
The distance the spring is compressed by force, mm,
(Cylindrical probe)
(Conical probe)
-Elastic coefficient of the spring, 0.2kg/mm ​​for thick springs and 0.1kg/mm ​​for thin springs,
Radius of cylindrical probe, mm;
Deepness of probe into the soil, mm;
Radius of the bottom of the conical probe, mm,
Height of the conical probe, mm.
Additional remarks:
This standard was proposed by the Ministry of Forestry of the People's Republic of China and is under the jurisdiction of the Forestry Research Institute of the Chinese Academy of Forestry. This standard was drafted by the Forest Soil Research Office of the Forestry Research Institute of the Chinese Academy of Forestry. 138
(2)
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