Patent ID: 8698076
Filing Date: 2014-04-15
Classification: G01N

Abstract:
1. A differential mobility analyzer classifying charged particles according to electrical mobility, the differential mobility analyzer comprising: a classification tank including n electrodes (where n is an integer equal to or greater than 3), each electrode having a planar shape, disposed in sequence in such a manner that the electrodes oppose each other as pairs, each pair having a predetermined space provided each of the electrodes, each of the n electrodes having at least one slit through which the charged particles pass; a gas supply section supplying the classification tank with sheath gas; and a voltage supply section applying a predetermined voltage between each of the pairs of the electrodes disposed opposing each other in the classification tank, wherein the classification tank includes (n−1) stages of classification sections for classifying the charged particles, each of the classification sections being formed by a respective one of the pairs of the electrodes disposed opposing each other, and each of the classification sections having a sheath-gas inlet, wherein the gas supply section controls a flow rate of the sheath gas supplied to the classification tank per classification section, wherein the gas supply section includes: (i) gas supply tubes connected to each respective sheath-gas inlet of the classification sections; and (ii) gas supply controlling means provided to each of the gas supply tubes, and wherein the sheath gas is flowed into at least one pair of adjacent classification sections in such a manner that the sheath gas is flowed into one classification section of the pair of adjacent classification sections in a direction opposite to that of the other classification section of the pair of adjacent classification sections.