Patent ID: 9709530
Date: 2017-07-18
CPC Classifications: B08B,G01N,G06K,H01J

Claim:
1. A method of managing polarity switching, comprising: operating in a first mode an ion mobility spectrometer comprising a repelling grid with a first voltage, a gating grid with a second voltage, and a fixed grid with a third voltage, and wherein the first mode is characterized by the first voltage being more positive than the second voltage, and the second voltage is more positive than the third voltage, and the third voltage is greater than zero; operating in a second mode the ion mobility spectrometer, wherein the second mode is characterized by the first voltage is more negative than the second voltage, and the second voltage is more negative than the third voltage, and the third voltage is less than zero; transitioning between the first and second modes, wherein during the transitioning the first voltage is more positive than the second voltage, the second voltage is approximately equal to the third voltage, and the second voltage is more negative than the first voltage when the first voltage is approximately equal to the third voltage.