Patent ID: 7884614

Claim:
An apparatus for measuring water content in foundry sand, comprising: a device of electrodes for measuring water content in foundry sand that includes: a plurality of conductive elements concentrically disposed in a longitudinal direction with certain intervals between them, wherein the conductive elements form an annular shape, a retaining element to retain the plurality of the conductive elements, wherein the retaining element has an electrical insulating property and a cylindrical shape having the same diameter as the conductive elements, two conductive wires to connect alternate respective elements of the plurality of conductive elements so that the conductive elements form two poles, wherein the two conductive wires pass through a cavity in the retaining element, and means for measuring temperature disposed in a cavity in the retaining element, wherein a distal end of the means for measuring temperature protrudes outside the retaining element, means for supplying a constant electric current having a rectangular wave and a low frequency to the conductive elements of the device of electrodes through the two conductive wires, means for measuring and stabilizing a voltage generated between the two conductive wires by an electrical current flowing between the conductive elements through the foundry sand, means for correcting the voltage measured and stabilized by the means for measuring and stabilizing the voltage based on the temperature of the foundry sand measured by the means for measuring temperature, and means for calculating the water content in the foundry sand based on the voltage corrected by the means for correcting the voltage.