METHOD AND INSTRUMENT FOR MEASURING UNSATURATED MOISTURE IN EARTH AND SAND

摘要

PROBLEM TO BE SOLVED: To measure the unsaturated moisture in earth and sand by making the detection of the equilibrium condition of the water level in the earth and sand easier. ;SOLUTION: At the time of measuring the pf value of an earth-and-sand sample 3, water is poured into a sand column 2 until the water level in the column 2 reaches the upper end of the column 2. Then a negative-pressure area is formed below the earth-and-sand sample 3 by draining the column 2 by opening an electromagnetic control valve 7 and the weight variation of the sample 3 is measured by means of a weight measuring means 6. Sensors 8 which measure the water level from the variation of the resistivity R of the column 2 are buried in the column 2 and the outputs of the sensors 8 are inputted to a measurement control operator 9. The operator 9 also inputs the output signal of the weight measuring means 6 and outputs a signal which instructs the opening/closing of the electromagnetic control valve 7 to the valve 7.;COPYRIGHT: (C)1998,JPO