CHELMSFORD, Mass., Nov. 28, 2012 — The McPherson Model DP100 is a high-vacuum pumping tee with a removable conductance-limiting aperture. The tendency of pressure to equalize in vacuum systems can interfere with experiments or prevent some detectors from operating properly. The DP100’s aperture creates a transition between an area of high pressure and a vacuum spectrometer or an experimental chamber at lower pressure To best match optical systems, apertures with circular or rectangular cross sections are available. The DP100 can allow up to three orders of magnitude pressure differential, depending upon the size of the conductance-limiting aperture and the capacity of the mounted pump. The pressure ratio increases linearly with the speed of the high-vacuum pump. The system can be used as a differential pumping section or as a pumping or gauging tee, gas inlet or electrical feed-through. It is offered with a range of fittings suitable for use with commercial vacuum components as well as beam apertures tailored for specific applications.