What is the significance of hydrometer analysis?
The hydrometer analysis of soil, based on Stokes’ law, calculates the size of soil particles from the speed at which they settle out of suspension from a liquid. Results from the test show the grain size distribution for soils finer than the No.
What is the significance of hydrometer method in geotechnical engineering?
In geotechnical engineering, hydrometer analysis is primarily used to know the grain size distribution of a fine grained soil.
How do you calculate hydrometer?
Insert the hydrometer in the measuring cylinder containing about 700 ml of water. Take the readings of the hydrometer at the top and bottom of the meniscus. The difference between two readings is taken as meniscus correction (Cm) which is a constant for a hydrometer.
What is hydrometer used in soil mechanics?
Hydrometer method is used to determine the particle size distribution of fine-grained soils passing 75 µ sieve. The hydrometer measures the specific gravity of the soil suspension at the center of its bulb. The specific gravity depends upon the mass of solids present, which in turn depends upon the particle size.
What is checked by hydrometer?
A hydrometer is an instrument used to determine specific gravity. It operates based on the Archimedes principle that a solid body displaces its own weight within a liquid in which it floats. Hydrometers can be divided into two general classes: liquids heavier than water and liquids lighter than water.
How do you calculate soil particle size?
In soil analysis, the proportion of gravel and larger particles is determined by first grinding the soil to disaggregate it and then passing it through a 2 mm sieve. What remains in the sieve is weighed and it’s proportion calculated as a percentage of the whole soil sample.
What is a hydrometer used for in a soils laboratory?
By measuring suspended solids in sedimentation cylinders, hydrometers are able to measure a soil’s particle-size distribution. To perform a hydrometer analysis the test specimen is combined with a dispersing agent and test water. A hydrometer is then used to take readings at specific time intervals.
Is code for hydrometer analysis of soil?
GRAIN SIZE ANALYSIS OF SOIL BY HYDROMETER, IS: 2720 (Part 4): 1985. Scope: To determine grain size of soils fraction passing through 75 micron IS sieve.
What is the purpose of dispersing the soil in the hydrometer method of soil texture determination?
Dispersant solution (e.g. sodium hexametaphosphate) is added to 40 g of soil and the soil is mechanically stirred on a shaker. Dispersant solution separates all the clay particles and breaks apart the soil aggregates.
Do hydrometers require calibration?
Temperature correction is necessary because the density of water varies with temperature, and wort is mostly water. Most hydrometers are calibrated at 60 °F (15.6 °C), but some are calibrated at other temperatures such as 58 °F (14.4 °C), 68 °F (20 °C), or even 70 °F (21.1 °C).
How is the hydrometer used in soil analysis?
The hydrometer analysis is a widely used method of obtaining an estimate of the distribution of soil particle sizes from the #200 (0.075 mm) sieve to around 0.001 mm. The data are plotted on a semi-log plot of percent finer versus grain diameters to represent the particle size distribution.
Why do you need a hydrometer for sieve analysis?
Both sieve analysis and hydrometer analysis are required to obtain the complete gradation curve of the coarse and fine fraction of many natural soils. Hydrometer analysis is essential for obtaining the complete particle size distribution of such soils.
How are particle size distributions used in hydrometer analysis?
Particle size distribution obtained from sieve analysis may be combined with the data from a hydrometer analysis to produce a complete gradation curve. It is possible to approximate the percentage of silt and clay particles present in the finer portion from the hydrometer analysis.
What should be included in a hydrometer report?
Your report should include the following: Analysis of the test results – Complete the table provided and show one sample calculation. Draw the grain size distribution curve for the data from the hydrometer analysis only and the combined grain-size distribution curve.