After mixing the air-dried soil with the prepared reagents solution do we absolutely need to pour them through a sieve again? I have read in one document where after using air-dried soil through a 2-mm sieve and for the determination of clay and silt, the suspension was not transferred through a sieve again only for the determination of sand where sand was transferred through a 50 um sieve. Will we lay down the hydrometer and temperature at the same time? When we let stay overnight the prepared solution, do blank treatment needs too? Can we adjust the temperature? If we need 20 degree Celsius and our thermometer is graduated till 30 degree in this case what can we do?
k is not a constant, it depend upon the specific gravity of the soil and the temperature of the suspension and the liquid's viscosity. The origin of the equation is D = sqrt(30n/980(G-g) * L/t) Where :- n = viscosity value. G = specific gravity of the soil. g = specific gravity of the liquid.
Hi, could you show us different Hydrometer with different scales and different calculation how to determine percentages of clay, silt and sand? Could we operate with the Hydrometer without thermometer, Fahrenheit?
You need to allow the dispersion agent more contact time with the material to ensure the individual grains of the material don't stick together. I believe per ASTM, there should be a 1hr pre-soak, however for educational purposes, 15min will work. You should not dump the agent in with the sample and go directly to the blender step.
Can we do all of the test without electric stirrer and correction? Using an iron stirrer instead of electric stirrer and use an alternative procedure that make sure we do not need any corrections.
Great walk-through! What is the corrected length? Is it some arbitrary value, or does it relate to the hydrometer above mixture? Or some third option... 🙄
PT in this equation (#3) is the Percent of the Total sample used in this Hydrometer Analysis (around 50g in this video). The material used in this analysis came from the material that passed the #200 sieve in the shaker portion of the gradation test, but is not necessarily all of that material.
why don't you record the temperature of soil solution by thermometer in the measuring glass before you drop the hydrometer down into it? I think the temperature is very significant factor to determine the calculation result
For anyone who may be watching this for educational purposes: Not all hydrometers read from the bottom of the meniscus. I work in a soil testing lab and ours reads from the top. If you are not sure which one yours reads at then you can put it in distilled water and it will read 1.0 at the correct part of the meniscus.
