The soil free swelling rate tester is suitable for the free swelling rate of clay. The free swelling rate is the ratio of the difference between the volume of the loosely dried soil sticking in the water and the air and the volume of free accumulation in the air. Used to determine the expansion characteristics of unstructured loose soil sticking to water. This instrument complies with the requirements of the Ministry of Communications' JTJ-2000 standard. It is used to determine the expansion rate of stone in liquid. It is widely used in various scientific research units, schools, mines, metallurgy, railways, transportation and other departments.
Main technical parameters of soil free expansion rate tester:
★ No neck funnel
★ Measuring Cup
★ Scale: dial indicator with a range of 5mm and an accuracy of 0.001mm
★ Water tank: 160 × 160 × 130mm
★ Specification of the sample: Cylinder Φ50 ～ 60mm, the height is approximately equal to the diameter. The side of the cube is 50 ～ 60mm.
★ Dimensions: 500 × 500 × 150mm
★量筒中土样沉积后约每隔5h记录一次试样体积，体积估读全0.1 mL。读数时要求视线与土面在同一平面上，若土面倾斜，取高低面读数的平均值。当两次读书差值不大于0.2 mL时，即认为膨胀稳定。用此稳定读数计算自由膨胀率。
★WX-2000土壤自由膨胀率测定仪按下列公式计算土样的自由膨胀率： FS=V-V0／V0 X 100 式中：FS一自由膨胀率，％，计算至1％； V-土样在量筒中膨胀稳定后的 体积，mL； VO-量土杯容积，mL，即干土自由堆积体积。
Test of soil free expansion rate tester:
★ Take a representative air-dried soil sample and crush it so that it all passes through a 0.5mm sieve. After mixing, take about 50g into the soil box, move it into an oven, bake it at a constant temperature at 105 ~ 110 ° C, and take it out in a dryer to cool to room temperature.
★ Install the neckless funnel on the support, the lower mouth of the funnel is aligned with the measuring cup, and maintain a distance of 10mm from the mouth of the cup, as shown in the figure.
Take out the soil sample from the coal dryer, pour the soil sample into the cup with a spoon, scrape the soil surface along the mouth of the cup when full, and then pour the soil sample from the measuring cup into the spoon. The illustration is still centered in the lower mouth of the funnel. Pour the soil sample in the spoon once and then remove the funnel. Use a flat-blade knife to gently scrape the excess soil sample perpendicular to the mouth of the cup (to prevent vibration), and weigh the mass of soil in the cup.
★ According to the regulations 3, two samples are weighed and measured in parallel. The difference between the two masses shall not be greater than 0.1g.
★ Put the A cylinder on the test bench, inject 30mL of distilled water, and add 5mL of 5% analytical pure sodium chloride solution, and then pour the soil sample in the soil cup into the volume.
★ Stir the suspension with a stirrer. The stirrer should be lowered to the bottom of the liquid surface and stirred 10 times (about 10s). Remove the stirrer, rinse the particles attached to the stirrer into the graduated cylinder, and rinse the graduated cylinder. Inner wall, make the liquid level in the graduated cylinder about 50ml. At the scale.
★ Record the sample volume every 5 hours after the soil sample is deposited in the graduated cylinder. The volume is estimated to be 0.1 mL. When reading, the line of sight should be on the same plane as the soil surface. If the soil surface is inclined, take the average of the high and low surface readings. When the difference between two readings is not greater than 0.2 mL, the expansion is considered stable. Use this stable reading to calculate the free expansion rate.
★ WX-2000 soil free expansion rate tester calculates the free expansion rate of soil samples according to the following formula: FS = V-V0 / V0 X 100 where: FS-free expansion rate,%, calculated to 1%; The volume after expansion and stabilization in a graduated cylinder, mL; VO-volume of measuring cup, mL, that is, the volume of dry soil free accumulation.
★ Wipe clean immediately after use and put in a dry place.