Method and apparatus for measuring the toner concentration and the amount of electric charge of a two-component developing agent

摘要

A method and an apparatus for measuring the toner concentration and the amount of electric charge, capable of simultaneously measuring the toner concentration and the amount of electric charge easily and maintaining high precision using a simple device. A method of measuring the toner concentration and the amount of electric charge of a two-component developing agent, by filling a unit cell having a mesh in the lower portion thereof and a small ventilation port at the upper central portion thereof with a two-component developing agent consisting of a toner and a magnetic carrier, creating a downward stream of the developing agent at the central portion of the unit cell and an upward stream of the developing agent along the walls of the unit cell relying upon the suction through said mesh, discharging the separated toner out of the unit cell through the mesh, calculating the toner concentration from the reduction in the weight of the developing agent in the unit cell or from the amount of the discharged toner and calculating the amount of electric charge from the amount of electric charge of the unit cell.