From this he concluded that the column of liquid is held up not by pull from the vacuum above but by push from the weight of air (the atmosphere) on the open surface of the bucket. Some pumps work by ...From this he concluded that the column of liquid is held up not by pull from the vacuum above but by push from the weight of air (the atmosphere) on the open surface of the bucket. Some pumps work by repeatedly expanding a volume, so that the gas expands into the bigger space, then gets separated from the area that is being evacuated. (See some images on Wikipedia.) Or we could absorb the gas molecules onto a surface to remove them the space being evacuated.
A mass spectrometer has four essential elements: a means for introducing the sample to the instrument, a means for generating a mixture of ions, a means for separating the ions, and a means for counti...A mass spectrometer has four essential elements: a means for introducing the sample to the instrument, a means for generating a mixture of ions, a means for separating the ions, and a means for counting the ions. In Chapter 20.2 we introduced some of the most important ways to generate ions. In this section we turn our attention to sample inlet systems and to separating and counting ions.
