Patent ID: 8987663
Filing Date: 2015-03-24
Classification: H01J

Abstract:
1. A mass spectrometer comprising: a high pressure region and a low pressure region which are interconnected by an orifice, wherein the high pressure region is substantially at atmospheric pressure; a housing arranged in the high pressure region and around the orifice, wherein the housing has an inlet in communication with the orifice such that components from a sample to be analysed may enter the housing from the high pressure region and then pass through the orifice into the low pressure region, and wherein the housing has an outlet opening in communication with the orifice; and means to draw gas from the high pressure region in through the inlet opening, towards the orifice and out of the outlet opening, wherein the means to draw gas draws the gas adjacent to and past the orifice and then out of the outlet opening, and wherein the gas drawn from the high pressure region contains the components; wherein the inlet opening has a larger cross-sectional area than the orifice and is located a distance upstream of the orifice.