Moisture Content Determination Using Rapid Moisture Meter

目的

该测试的目的是快速确定土壤的水分含量，而无需等待水分蒸发。

土壤Specimen

This test requires about 6 g of soil sample. Sand requires no special preparation. Coarse powders may be ground and pulverized. Cohesive and plastic soils and material are tested with addition of stee1 balls in the pressure vessels.

Equipments

1. Rapid moisture meter

Procedure

1. The apparatus required for the test includes one metallic pressure vessel with clamp for sealing cup and a gauge calibrated in percentage water. One counterpoint balance, a scoop for measuring calcium carbide and three steel balls of 12.5 mm diameter and one steel ball of 25 mm diameter.
2. Set up the balance and place the sample in the pan till the mark on the balance arm mass lines up with the index mark.
3. Unclamp the clamping screw to move the U-clamp off the cup. Lift off the cup. Clean the cup and the body.
4. Hold the body horizontally and gently deposit one level scoopful of calcium carbide halfway inside the chamber. Then lay the chamber down without disturbing the calcium carbide charge and transfer the soil weighed out as above from the pan to the cup.
5. Holding cup and chamber approximately horizontal bring them together, without disturbing sample or calcium carbide, bring the U clamp round and clamp the cup tightly into place.
6. 计向下,动摇湿度计up and down vigorously for 5 seconds, then quickly turn it so that the gauge is upwards, give a tap to the body of the moisture meter to ensure that all the contents fall into the cup.
7. Hold the rapid moisture meter downward, again shake for 5 seconds, then turn it with gauge upwards and tap. Hold for one minute. Repeat this for a third time. Once more invert the rapid moisture meter and shake up and down to cool the gas. Turn the rapid moisture meter with the gauge upwards, and dial horizontal held at chest height when the needle comes to rest, take the reading. The readings on the meter are the percentages of water on the wet mass basis.
8. 或者，三个较小的钢球可以与土壤一起放置在杯中，并且与吸收剂一起较大，并且像往常一样密封单位。保持快速湿度计垂直，使杯子中的材料落入身体。现在水平握住单元，将其旋转10秒，使球绕组的内部圆周滚动。休息20秒。重复旋转 - 休息循环，直到规格读数是恒定的（通常需要4到8分钟）。请注意像往常一样的阅读。
9. 最后通过打开夹紧螺钉缓慢（远离操作员的压力（远离操作员），并用刷子清空内容物并清洁仪器。
10. Calculate the water content (W) on the dry mass from the water content (M) obtained on the wet mass basis as the reading on the rapid moisture meter, as follows:

W = [M/(100-M)]*100

Where,

W = percent water content of the dry mass

M = percent water content of the wet mass

Reference

IS 2720 (Part II) – 1973