Abstract: Electrical current driven through one or the other of two coils (20 and 22) draws a ferromagnetic bob (28) along a chamber (26) containing a liquid whose viscosity is to be measured. The current that flows through the coil includes an AC component, and the resultant magnetic field causes in the other coil an AC voltage whose magnitude depends on the bob's position. A position detector (38, 40) monitors the electromotive force thus induced and concludes that the ferromagnetic bob has reached a predetermined end-of-travel position when the magnitude of the electromotive force has fallen to a predetermined fraction the maximum value that it had attained during the stroke, and a coil driver (36, 38) switches current drive from one coil to the other so as to begin driving the bob in the opposite direction.

Abstract: A method for forming a structural panel such as for a bridge deck includes providing a first and a second sheet formed by fibers and settable resin and laminating the sheets with a plurality of parallel side by side connection members. The connection members are formed by filament winding around a core using primarily a large wind angle followed by a final shallow angle of wrap. The connection members are triangular in cross section and each is inverted relative to the next so that the sides are in contact. The connection members are connected together while the resin is uncured so that during lamination they cure together to allow integration of the resin, close matching of the shapes so that the resin at the junction remains thin and intermingling of the filaments. The connection members are dry wound on a core and the resin is applied by infusion. The core carries reinforcing members to tailor strength as required along the length of the member.

Abstract: A system for continuously monitoring fills of liquid such as fuel oil in a tank, and the condition of the liquid. A dual in-line air bell structure senses fluid pressure at upper and lower locations inside the tank, the locations being spaced a known distance apart from one another in a normal direction relative to the tank. Processing circuitry responsive to the fluid pressures obtained via the air bell structure, determines quantities of liquid contained in the tank at certain times and produces corresponding outputs such as gallons of liquid delivered to the tank at each of a number of delivery times, and total gallons of liquid in the tank as the liquid is consumed. The air bell structure is formed with upper and lower air bell sections joined end-to-end along a common axis. Each of the air bell sections includes at least one aperture in its wall to define a cross-section through the air bell section.

Abstract: A densitometer (10) provides a chamber (24) within which a ferromagnetic bob (27) is shuttled back and forth by alternate driving of two coils (32 and 34). Measurement circuitry (FIG. 2) determines the density of the fluid inside the chamber (24) by comparing the stroke times in opposite directions.

Abstract: A viscometer (10) includes a chamber-defining cylinder (22) within which a bob (26), including a ferromagnetic collar (30), is shuttled back and forth by alternate driving of two coils (32 and 34). Measurement circuitry (FIG. 2) determines the viscosity of fluid inside the chamber (24) by measuring the time required for the bob (26) to make a round trip consisting of one stroke in each direction. By employing round-trip time rather than single-stroke time, the viscometer (10) reduces the sensitivity of the viscosity measurement to orientation with respect to gravity.

Abstract: A viscometer (10) employs a tube (12) with a check valve (30) at one end and a ferromagnetic bobbin (16) disposed inside and freely movable with respect to it. A pair of coils (38 and 40) are alternately energized, causing the bobbin (16) to move against fluid in the tube in one direction, in which the check valve (30) prevents fluid flow, and in the other direction, in which the check valve (30) permits fluid flow within the tube. When the bobbin (16) moves in the direction in which the check valve (30) permits flow, it draws a new sample of fluid into the tube, and the time required for the bobbin (16) to move in the other direction, in which fluid flow is prevented by the check valve (30), is measured as an indication of the viscosity of the fluid. The position of the bobbin is sensed by measuring the mutual inductance between the coils (38 and 40).