Hydrometer Method Accessories

As silt and clay particles that are finer than sieves No. 200 Determined by sedimentation. The densitometer is used in order to collect the required data during the sedimentation. Hydrometer test is based on Stokes' law, where related in the diameter of a singular spherical object in the time required to fall within a set distance in a given viscosity of liquids.

Hydrometer test is based on the principle that Larger particles (and therefore heavier) than finer particles (and therefore lighter) of soil in distilled water will faster fall down. The experimental method is approximate because many small particles are not spherical but also the soil often with sheet shape therefore in hydrometer test, used an orb (sphere) with the Equivalent diameter to determine the size of particles, while the particle size distribution test puts criterion of square mesh size of the sieve. Hydrometer tests are based on soil and seed sedimentation in the water, when the soil is well stirred, seeds suspended in terms of shape, size and weight are sedimentation with different speed. For simplicity, it is assumed that all are spherical grains of soil and sedimentation velocity can be expressed according to Stokes' law. In the lab, testing hydrometric in a sedimentation cylinder with 40 grams samples of soil that takes place on the grill and dry which was rejected of sieves No: 200, and mix in scaled cylinder to the intended volume, usually Sodium Hexa Meta Phosphate used as scattering material, mix by stirrer, mixed and by adding distilled water, its volume will increase to 1000cc. A hydrometer, which used in the hydrometric tests must obtain following specifications.

1. We need to see the hydrometer in a solution prepared using sodium hexa meta phosphate in what grade will take place. Hydrometer because these hydrometers are designed to distilled water so it is necessary to understand if the hydrometer is placed in solutions we have to know (find) in which degree is the zero of the indicator.
2. Another point is the temperature of the mixture. The hydrometer is calibrated at 20 ° C and the temperature of the mixture is important to us, after obtaining the given numbers of the tables. Correction factors are obtained for each reading and then we fix the numbers, to give accurate results acceptable to relevant experts.

Hydrometric testing equipment