ELECTRONIC LEVEL SENSOR AND TIMER BASED FALLING HEAD SOIL PERMEAMETER

摘要

Determination of hydraulic properties such as porosity and permeability of soil is of paramount importance in hydrology and civil engineering. In order to achieve greater accuracy in determination of permeability of soil using falling head permeameter, the two important known constraints of human monitoring error in noting the falling water level between two selected levels and elapse time between these two levels had overcome through electronically sensing the levels between two selected points and activating the timer clock automatically by the pulses coming from sensor. The precision in measurement of time lapse in 1/100^thof a second enables greater accuracy in estimation of permeability. Provision of perforated Teflon disc above and below the soil core facilitates in application of water uniformly over the entire surface area of soil core at top and similar way permeated water leaving the soil core uniformly without any obstruction. The use of carbon steel seamless tube while collecting soil core facilitated in undisturbed soil core recovery from desired depth section. The permeability test was conducted for various sorted sands of different size ranges and each sample was subjected to repetitive tests and elapsed time for each test was recorded from timer unit. Coefficient of Permeability was calculated for each test. The lab experiment conducted for sorted and unsorted sediments has yielded a consistent performance of Electronic level sensor and timer based falling head soil permeameter.