Abstract: Provided are apparatuses and methods for mixing gases. The apparatuses are suitable for use in the manufacture of an electronic device. The apparatuses include a gas mixing manifold. A first, bulk gas source is connected to introduce a flow of a first gas to the manifold. A second gas source is connected to introduce a flow of a second gas to the manifold. The first and second gases are mixed in the manifold, thereby forming a gas mixture. A conduit is connected to one or more point of use for introducing a flow of the gas mixture thereto. The present invention is particularly applicable in the semiconductor manufacturing industry.

Abstract: A method is described to remove condensible vapors in highly compressed gases without affecting the original particle spectra and concentrations. The vapors are separated from particles primarily through diffusion mechanism and collected on cold surfaces. Four important parameters are the length, the flow rate, the temperature, and the diffusion coefficients of the vapors to be removed. Important applications include sampling particles from high pressure gases and condensible vapor-free filling for ultra-pure cylinder gases.

Abstract: A follower response control circuit for a reference level establishing system having positive and negative follower circuits, each having means for defining a pre-established time constant producing, respectively, a positive peak signal and a negative peak signal in response to an input signal, and means responsive to the peak signals for establishing a reference level, including means for defining a second time constant for one of the follower circuits; switching means for selectively switching the means for defining a second time constant in and out of that one of the follower circuits; a direction detector circuit for determining whether the input signal level is moving toward the polarity of the peaks followed by that one of the follower circuits; a level detector circuit for determining whether the input signal is of the same polarity of the peaks followed by that one of the follower circuits; and a switch control responsive to the detector circuit for operating the switching means to introduce the means