Beckman Instruments, Inc.

Clement P Aime

Donald L Horrocks

Peter J Coassin

William H Shope

A compact manifold for distribution of fluids (gas or liquid or combination thereof). The manifold has a block having fluid channels provided therethrough between two faces of the block. Against one face, a plate is fastened which swages ferrules between the plate and the block to tightly connect fluid conduits through the plate to the block. On the opposite face of the block, a manifold plenum is formed in a groove between a manifold plate and an o-ring. The o-ring is pressed against the manifold plate by a back plate and both plates are securely fastened onto the block such that the holes in the manifold plate are aligned with the fluid channels in the block. Checkvalves are positioned between the block and the manifold plate to prevent backflow. The above-mentioned components are positioned into their respective places and are secured upon the tightening of the fasteners. The manifold is configured with at least two plenums each having a group of distribution outlets. A checkvalve is provided at each outlet on the plenums. The plenums are connected to a single source in cascade, whereby the plenums are connected via a length of small diameter tubing which serves as a barrier against diffusion of fluid between the plenums. Thus, there are at least two checkvalves and a diffusion barrier tubing in the flow path between two reagent containers.

Fluid distribution manifold

An automatic spectrum scanning technique for use in a proportional counting instrument, such as a gamma counter or liquid scintillation counter, by means of which a pulse-height or energy spectrum of a sample can be obtained automatically and without multichannel instrumentation. A pulse-height analyzer in the counting instrument has its upper and lower discriminator limits set to define a relatively narrow counting window, and the limits are successively changed to scan the window across the energy spectrum and thereby obtain an accurate measurement thereof. Counting at each increment of the scan is continued for a preselected maximum time interval, but is quickly terminated if the count rate falls below a preselected low threshold value, and is terminated early if the count rate is relatively high, i.e., if the statistical error value associated with the count is relatively low. A technique is also disclosed for correcting the counting statistics when the sample being analyzed has a relatively short half-life and the radioactivity of the sample falls off at a relatively rapid rate.

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Huntington Beach, CA, United States of America

Clement P Aime