Moonay D.J.,Engineering Laboratories Inc.
American Laboratory | Year: 2012
Viscosity measurements are an important tool for materials characterization and a sensitive measure of material changes. Many operators use the Helipath™ Stand Model D system in which a motorized stand lowers a viscometer head while a thin T-shaped spindle rotates at a low to moderate speed, such as 10 rpm or less. The spindle effectively carves a helical path down through the sample, continuously testing fresh material points are taken over time, and the results are averaged to provide a meaningful QA/QC measure. This technique provides very useful correlations to process engineering data for certain rheologically complex products. Vane rheometry is also useful in measuring yield stress, the stress required to make a solid-like material flow like a liquid. The test automatically stops when a significant, user-specified, decrease from the peak value is detected. Appropriate selection of spring torque ranges, spindles, and speeds, may be used to monitor viscosity changes over time with a consistent technique.
Ghaderi A.,Nidec Corporation |
Umeno T.,Engineering Laboratories Inc. |
Sugai M.,Toyota Central R&D Labs.
IEEE Transactions on Industrial Electronics | Year: 2016
In an electric drive vehicle (EDV), the available voltage on a dc-link is limited, and so the inverter output voltage and, consequently, the line motor maximum speed are limited. The fundamental voltage of the inverter output is increased approximately 27% using a square wave (SW) switching pattern instead of a sine wave switching pattern. However, this pattern can only be used at high speeds, and at lower speeds a pulsewidth modulation (PWM) pattern should be used. In order to achieve proper control, the switching pattern should be changed seamlessly. In the present paper, a new PWM scheme for single-mode seamless control of Vernier motors is proposed. In the proposed scheme, the reference voltage is modified to change the switching pattern continuously so that the voltage changes smoothly from a high-frequency pattern to an SW and voltage discontinuity does not occur. Experimental results reveal that the inverter-switching pattern changes smoothly from a sinusoidal PWM pattern to an SW pattern, and so seamless control from the constant-torque region to the constant-power region, and vice versa, is achieved. Since the proposed scheme is a single-mode control, it is much simpler than current technologies, which are based on multimode controllers. Also the proposed method has a lower total harmonic disturbance (THD) as well as a lower harmonic distortion factor (HDF) compared to some existing methods. © 1982-2012 IEEE.
Mcgregor R.G.,Engineering Laboratories Inc.
American Laboratory | Year: 2013
New rheometers represent the most advanced capability in the worldwide market for viscosity and yield stress measurement. Ease of use is facilitated by new touchscreen interfaces, which have become the standard due to the market proliferation of every day handheld devices, such as smartphones, tablets, etc. Viscosity test data can now appear live on the screen in graphical format with the added benefit of showing trend behavior. The data on the screen, permit visual acceptance or rejection at a glance. The instrument by itself can actively monitor the measured viscosity and yield stress values and report whether the data fall between allowable QC limits established by the user. These improvements help to increase both the quantity and quality of data generated per test. They also streamline the test in terms of the time required to execute.
Engineering Laboratories Inc. | Date: 2013-08-07
Viscosity or rheology measuring instrument utilizing Hall Effect or like magnetic coupling with parts mounted on driving and driven rotational assemblies.
Engineering Laboratories Inc. | Date: 2013-02-01
Disclosed herein are a variety of systems and methods for entry of data relating to an electrical power delivery system using a web-based interface. One embodiment may include a computer program product having a client-side module to communicate with a server-side module. The client-side module may further include a web browser interface module to retrieve data entered by an operator into a data entry field in a web browser, a user interface module to display variable length data to a user via the web browser, and a communication module to manage communication with the server-side module. The communication module may further be configured to generate an object comprising data entered by the user into the web browser, transmit the object to the server, and receive a response from the server.