NY/T 1121.3-2006
ActiveSoil Testing Part 3: Method for determination of soil mechanical composition
土壤检测 第3部分: 土壤机械组成的测定
Catalogue
前言 → 1 应用范围 → 2 测定原理 → 3 主要仪器设备 → 4 试剂 → 5 分析步骤 Foreword → 1 Scope → 2 Determination Principle → 3 Main Instruments and Equipment → 4 Reagents → 5 Analysis Procedure
Scope
This part is applicable to the determination of mechanical composition of all types of soil.
本部分适用于各类土壤机械组成的测定。
Keywords
Application Summary AI generated
Analysts in agriculture, environmental science, and geology use this standard to determine the distribution of particle sizes in soil. It helps classify soil texture, which is essential for soil management, crop selection, and land improvement. This standard is important for accurate soil resource assessment and sustainable land use.
农业、环境及地质领域的检测人员使用本标准来测定土壤中不同粒径颗粒的含量。通过该方法可以了解土壤的质地类型，为土壤分类、农田改良和作物种植提供科学依据。该标准对于土壤资源评价和合理利用具有重要意义。
AI Summary AI generated
This standard specifies the method for determining soil mechanical composition, applicable to all soil types. Based on Stokes' law, it uses a Type A soil hydrometer to measure suspension density changes and calculate particle size distribution. Key steps include sample weighing, selecting dispersant according to soil pH (sodium hexametaphosphate, sodium oxalate, or sodium hydroxide), and boiling with frequent shaking to prevent clumping. The method provides fundamental data for soil texture classification and agricultural use.
本标准规定了土壤机械组成的测定方法，适用于各类土壤。原理基于司笃克斯定律，使用甲种土壤比重计测定悬浮液密度变化，计算粒径分布。关键步骤包括称样、根据土壤pH选择分散剂（偏磷酸钠、草酸钠或氢氧化钠）、加热煮沸并摇动防止结块。该方法为土壤质地分类和农业利用提供基础数据。
Key Sentences extracted from text
本部分适用于各类土壤机械组成的测定。
试样经处理制成悬浮液，根据司笃克斯定律，用特制的甲种土壤比重计于不同时间测定悬液密度的变化，并根据沉降时间、沉降深度及比重计读数计算出土粒粒径大小及其含量百分数。
称取2 mm孔径筛的风干试样50.00 g于500 mL三角瓶中，加水润湿。
根据土壤pH加入不同的分散剂（石灰性土壤加60 mL 0.5 mol/L偏磷酸钠溶液；中性土壤加20 mL 0.5 mol/L草酸钠溶液；酸性土壤加40 mL 0.5 mol/L氢氧化钠溶液）。
在煮沸过程中要经常摇动三角瓶，以防土粒沉积于瓶底结成硬块。
This part is applicable to the determination of mechanical composition of all types of soil.
The sample is processed to form a suspension, and according to Stokes' law, a special soil hydrometer (Type A) is used to measure the density change of the suspension at different times, and the particle size and percentage content are calculated based on sedimentation time, sedimentation depth, and hydrometer reading.
Weigh 50.00 g of air-dried sample passed through a 2 mm sieve into a 500 mL conical flask, and wet with water.
Add different dispersants according to soil pH (for calcareous soil add 60 mL of 0.5 mol/L sodium hexametaphosphate solution; for neutral soil add 20 mL of 0.5 mol/L sodium oxalate solution; for acidic soil add 40 mL of 0.5 mol/L sodium hydroxide solution).
During boiling, shake the conical flask frequently to prevent soil particles from settling and forming hard lumps at the bottom.