Abstract: A device for converting a position of a float member in a rotameter in to an electrical output. Light from a light source is collimated into parallel light rays, at either or both opposing sides of a rotameter tube to greatly enhance accuracy of readings. The lightrays passing through the tube are detected by a linear optical array. A range of movement capable of being read by the linear optical array is extended by use of either a fiber optical array or a movable illumination device and linear optic array. The collimator(s) may be a linear array of one or two rows of cylindrical lenses sandwiched between a pair of plates. The linear optic array maybe arranged on opposite sides of the rotameter tube or may be on the same side there of. A light guide is used in the latter arrangement to guide light from the light source to a side of the rotameter tube opposite the linear optic array which may be a charge-coupled device(CCD).

Abstract: A movable piston is arranged within an open-ended cylinder, the piston having a peripheral groove for receiving liquid mercury to create a sliding gas-tight seal between the piston and the cylinder. The cylinder wall is provided with a plurality of openings, arranged to prevent mercury from escaping through said openings while permitting gas introduced into the interior of the cylinder to escape therefrom. When the piston reaches an equilibrium condition, the height of the piston represents the gas flow rate, which is determined by the flow rates through the total number of openings beneath the sliding seal. As an alternative embodiment, the flow rate is controlled by a downwardly moving piston. As another alternative embodiment, the piston is free to move up or down to compensate for fluctuations in pressure and/or flow rate within the cylinder.

Abstract: Measuring apparatus for calibrating flow meters and the like comprising a piston slidably mounted within piston cylinder means which receives gas passing through the flow meter being calibrated to cause the piston to be lifted. A precision encoder is rotated responsive to the movement of tape means aligned with the central axis of the piston and entrained about a pulley driving said encoder means. The tape is also connected to counterbalancing weight means for enhancing the sensitivity and accuracy of the measuring apparatus. The system electronics initiate operation of timer means upon the first pulse generated by the encoder means after operation of a start button and terminates the operation of the timer means upon the first encoder pulse generated after operation of stop button.Temperature and pressure in the piston cylinder are constantly monitored. These readings are employed at the time flow rate calculations are performed to correct the flow rate calculated to standard temperature and pressure.

Abstract: A marker device for ejecting a chemical marking substance, such as paint, onto nearby unauthorized persons or objects, comprising a chamber means for containing an isolated quantity of a chemical marking substance therein. The chamber is attached to a main body member. The main body contains an evacuating plunger means therewithin which is movable from a retracted into an extended position and which is telescopingly received within the chamber when moved into the extended position.A power mechanism which can be actuated to move the plunger along its longitudinal axis is incorporated within the main body along with a trigger mechanism for actuating the power mechanism, so that when triggered by unauthorized persons, the plunger forces the chemical marking substances to be ejected and dispersed in a selected direction.