Abstract: The concentrations of hyperfine particles in a fluid are monitored by flowing a predetermined quantity of the particle-containing fluid over a substrate in the presence of a force field which "collects" the particles onto the substrate. The particles may be deposited on the substrate according to size, so that one can readily ascertain not only the particle concentration in the fluid, but the size distribution of the particles as well. This technique greatly concentrates the particles so that one can usually detect and monitor materials having extremely small particulate concentrations in the fluid from which they are collected.

Abstract: A portable, lightweight, compact contaminated fuel detector uses a standard batch sampling technique. This is done through two series filters in a filter holder into a vacuum receptacle. The differential filter opacity is checked in a photocell fixture using a light whose intensity is first adjusted by potentiometer to a standard level using a milliammeter which is also read to determine each filter opacity. The compactness and weight reduction is accomplished using a lightweight box enclosure with a supporting deck carrying equipment including a hand-operated vertically oriented vacuum pump and careful arrangement of the pump within the enclosure relative to other elements of the system.

Abstract: An apparatus for identifying particles such as cells in a liquid suspension includes a particle scanning device containing a suspension of the particles. The suspension moves in a stream through a sensing zone in the device, which, for example, may be a Coulter type particle detector, and out of the sensing device to a waste receptacle. As each particle in the suspension passes through the sensing zone, it will produce a particle pulse whose measurements represent at least one physical characteristic of the particle. A particle collecting substrate is positioned adjacent the stream departing the scanning device. A counting device, coupled to the scanning device and the substrate, operates only in response to the particle pulse for each sensed particle selected to develop a particular count signal and to direct the stream and the selected particle therein to a particular location on the substrate corresponding to the particular counting signal.

Abstract: A device embodying a substrate having at least one longitudinal groove formed in a flat surface thereof for accommodating microstructures for microscopic examination.