Abstract: Methods for determining the gelation period of a gel solution are provided. The methods provided include introducing a first inert ball, or first inert hollow ball comprising a polymer solution, into a gel solution container containing a gel solution where upon the first inert ball, or inert hollow ball, reaching a bottom of the gel solution container, at least one subsequent inert ball, or inert hollow ball, is introduced sequentially into the gel solution container until the at least one subsequent inert ball, or inert hollow ball remains fixed in place prior to reaching the bottom of the gel solution container. Methods also include determining the gelation time of the gel solution based on a sum of distances traveled by the first inert ball, or inert hollow ball, and at least one subsequent inert ball, or inert hollow ball.

Abstract: An illustrative method for measuring a fluid viscosity that includes vibrating a tube containing a fluid of interest, obtaining a vibration signal from the vibrating tube, deriving a system energy loss rate measurement from the vibration signal, calculating an energy loss rate for the fluid of interest from the system energy loss rate measurement and a reference energy loss rate measurement, and generating a viscosity measurement of the fluid of interest based on the energy loss rate for the fluid of interest and a density of the fluid of interest.

Abstract: An electric motor (100) having a motor control system (400) including: —a current measuring means (402) for directly or indirectly measuring the electric current in the rotor windings (7) providing a rotor current value/s, —an ambient temperature measuring/estimation means (404) for measuring or estimating the ambient air temperature providing an air temperature value/s, —a rotor temperature estimation means (406, 407, 408, 409, 410, 411) for estimating a rotor temperature at least based on the rotor current value/s and the air temperature value/s, and—a current limiting means (405) for preventing overheating/burning of the rotor assembly (3) by limiting the electric current to the rotor windings (7) when the estimated rotor temperature exceeds a predetermined overheating threshold (412).

Abstract: An average-temperature compensated field device comprises a field module, a temperature-averaging sensor, a microprocessor, and an interface. The field module is configured to characterize a process parameter. The temperature-averaging sensor is configured to generate a compensation signal characterizing an extended region of the field device. The microprocessor is configured to compensate a process signal as a function of the compensation signal. The interface is configured to communicate the process signal via a field device communication protocol.

Abstract: A micro-rheometer for measuring flow characteristics such as viscosity, elasticity, and flow rate of a sample liquid combines well defined micro-fabricated flow channels having geometry changes forming a constriction region therein to a monolithically fabricated pressure sensor arrays. The pressure sensor array positions pressure sensors to measure the viscosity of the sample liquid while flowing in a uniform length of the flow passage and to measure the extensional viscosity while flowing through the constriction region of the passage. The invention can improve the measurement accuracy of the flow rate, viscosities, or elasticities over a wide range of shear rate. The accuracy of the viscosity over a broader range of shear rate or flow rate measurement over broader range of flow rates can be accomplished by employing monolithically integrated pressure sensors fabricated with different sensitivities disposed in a known manner.

Abstract: An improved micro slit viscometer includes a combined micrometer depth rectangular slit flow channel with monolithically integrated multiple pressure sensors in the flow channels and a pumping system that injects a test sample to the channel at a desired flow rate. Pressure sensing diaphragm of the monolithically integrated pressure sensors is smooth to minimize the flow disturbance thereby measuring accurate local pressures. With the measurement of the pressures at various locations of the channel the true viscosity of test sample can be calculated. The viscometer may consist of multiple flow channels and thus the true viscosity at multiple shear rates can be measured simultaneously for a given flow rate thereby obtaining a full viscosity curve as a function of shear rate of non-Newtonian liquids in a much faster manner. The viscometer needs only a miniscule amount of sample, which minimizes a waste of test material.

Abstract: An apparatus and methods for analysis of a petroleum product, specifically determining the viscosity of a sample, are disclose. The apparatus includes a sample reservoir for receiving a liquid sample and a pressure regulator for applying hyperbaric pressure to a sample within the reservoir. When pressure is applied to the sample reservoir, the sample is forced through a passageway and a pressure sensor monitors the pressure in the sample reservoir. A drop in the pressure can be used to determine when the reservoir is empty and sample viscosity can be calculated based on the time required to empty the reservoir.

Abstract: An apparatus and method for determining viscosity of a low viscous fluid. A narrow tube samples a fluid sample. The apparatus or capillary viscometer determines viscosity within average relative deviation of less than 2% over a range of viscosity greater than two decades by mass flow rate. The apparatus includes a glass capillary viscometer with thermal jacket, balance with serial interface, and software for computer interface.

Abstract: A pressure compensated sound transducer is provided wherein compensation and equalization of static ambient pressure variations occurring on the faces of at least one piezoelectric element is achieved by a mensural compensating duct communicating compensating fluid between two reservoirs, each located on an opposite face of a piezoelectric element. One reservoir is formed in the void of the support housing containing at least one piezoelectric element; the remaining reservoir is formed in the void between the housing and a sealed impermeable, compliant boot. The sealed boot prevents contamination of the compensating fluid from the external environment and loss of the compensating fluid to the outside environment.