Abstract: A device (15) for measuring the level of a fluid (24) in a container (17) comprising a frame assembly having a first arm (18) and a second arm (19), the first and second arms configured to move from a first folded position (20) to a second expanded position (21), a probe element (22) supported between the first arm and the second arm, the probe element having a sensing portion (34, 35) between the arms when the arms are in the second expanded position, the sensing portion configured to have a length (25) in contact with the fluid, an electrical circuit (26, 29) connected to the probe element, the probe element and the circuit forming a capacitor having a capacitance which is a function of the length of the probe that is in contact with the fluid, and the circuit configured to produce an output signal as a function of the capacitance.

Abstract: A shaped diaphragm as a part of a fluid processing disposable set acting as a centrifuge system rotor. The fluid processing disposable set has a variable-volume chamber and a fluid port. The shaped diaphragm defines a wall of the variable-volume chamber. The chamber is in fluid communication with the fluid port and is defined by a fixed wall and an elastic wall. The elastic wall is formed by the shaped diaphragm. The disposable set may also have a rotary seal coupled to the fluid port and fluidly coupled to the variable-volume chamber. The shaped diaphragm may be convoluted. The convolution may be a single fold and may have a plurality of folds located symmetrically about an axis. The shaped diaphragm may, alternatively, be essentially planar in an unstretched position while varying in thickness along a diaphragm dimension. Centrifuge rotors, systems, and methods for selective harvest of fluid constituents from a whole fluid are detailed.

Abstract: A pump unit for recovery of hydrocarbon liquid from atop water in a well includes a hydrocarbon pump intake with a linear probe for indicating the position of the pump intake relative to the hydrocarbon/water interface on a control panel, so that its relative position can be monitored and changed. The probe has a conductive member coated with a non-conductive coating, and is attached to a source of low frequency electrical signal. The strength of a signal output from the probe indicates the position of the probe, and the pump intake, relative to the hydrocarbon/water interface and controls a display on a control panel. Furthermore, the signal can be used to control the hydrocarbon/water interface relative to the pump intake by such means as pumped water from under the pump intake in a controlled manner to change said interface relative to the intake or by means of a motorized lift to reposition said pump intake relative to the interface.

Abstract: A monitoring system for determining the volumetric percentage of liquid nitrogen in a quantity of liquified natural gas (LNG) whose composition of liquified hydrocarbon gases is known, and which is stored at atmospheric pressure. The system includes a device, such as a temperature-dependent resistor connected to a power source, for producing an electric signal proportional to the temperature of the liquified gas. This temperature signal is subtracted from a reference signal which is equal to the temperature signal when the liquified natural gas does not contain any nitrogen, and which can be produced by a device such as a precision resistor connected to the power source. The differential signal output of the temperature and reference signals will be proportional to the volumetric percentage of nitrogen in the liquified natural gas, and a standard readout device, such as a voltmeter, can be calibrated to read the volumetric percentage of nitrogen from this differential signal.

Abstract: A liquid density measurement system comprises a capacitance probe and a temperature sensor both immersible in a liquid the density of which is to be measured. Signals derived from the probe and sensor are converted into respective electrical signals representing changes in the dielectric constant and temperature of the liquid respectively. These signals are scaled in a predetermined mutual ratio and then summated to give an output signal proportional to the density of the liquid. The scaling ratio is set according to predetermined liquid parameters such that the accuracy of the density represented by the output signal is unaffected by changes in liquid composition.

Abstract: A fuel tank alarm system comprises three density sensors disposed at different heights within a fuel tank. An electrical density signal produced by the lowest sensor is subtracted from the corresponding signals from the upper two sensors to produce two density-difference signals which are then compared with a reference signal. When an inverse density gradient of dangerous proportion exists in the fuel tank, one or both of the density-difference signals exceeds the reference signal in magnitude and an alarm circuit is actuated. The alarm circuit can automatically start a pump to circulate fuel in the tank and reduce dangerous density inversion of fuel therein.