The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
DC voltage measurement device is the key equipment in the DC transmission system, which is mainly used for system voltage measurement and providing voltage signals to the measuring instruments and secondary protection devices. With the rapid development of DC transmission and flexible transmission in China, DC voltage measurement device has been widely used and developed. High accuracy and high stability...
In this paper authors present the result of a study oriented to assess the metrological characteristics of measuring systems used for verifying the variation of the ratio errors and phase displacements of inductive voltage transformers vs. temperature. Experimental results show that the designed equipment as well as the set up realized can be considered as a benchmark for the verification of the variations...
A CMOS digital temperature measurement technique is reported, which doesn't require an explicit reference voltage during temperature to digital conversion. Instead, one of the inputs from the sensor core serves as the reference. After eliminating the need to use an external reference, we observe at least twofold increase in temperature estimation accuracy compared to the reference based traditional...
This paper investigates an innovative, non-invasive and contactless approach for respiratory rate detection in spontaneous breathing by using an industrial standard humidity and temperature sensor controlled by a microcontroller. Hardware and software have been designed and manufactured and for a spontaneous respiration simulation two different test beds have been developed and evaluated. Results...
The Thermal InfraRed Sensor (TIRS), an infrared (IR) radiometer developed at Centro de Astrobiología, is one the sensors that compose the Mars Environmental Dynamics Analyzer (MEDA) onboard NASA's Mars 2020 mission. It will measure the net thermal infrared radiation, reflected solar radiation at the surface, atmosphere temperature and surface skin brightness temperature using five different channels...
To study the deposition of particles on chip surface during the work of the thermal gas flow sensor, the paper analyzes deposition mechanism in depth by experiments to provide theoretical basis for reducing or avoiding particle deposition. The affecting factors of particle deposition such as electric field, the direction of sensor chip placement have been studied by monitoring the accuracy of flow...
The STC translation methods are used in many applications, such as prediction of energy yield, characterization of PV modules, and translation of current-voltage (I-V) curve from any conditions of temperature and irradiance, to any other conditions of temperature and irradiance. A comparative study has been done in this work to compare and contrast Anderson and Blaesser translation methods. The Isofoton...
Accuracy tests were performed on whole-current and transformer-operated electronic energy meters under conditions that reflected the actual adverse metering site conditions. Analysis of the test data reveals the deleterious effect of high ambient temperatures on the measurement accuracy and precision of electronic meter indications. Based on the study results, measures are recommended to address concerns...
This article deals with accuracy of indirect torque measurement of converter-fed induction motors. The measurement was held on both mid-(7,5 kW) and low-power (0,5 kW) motors supplied by Siemens SINAMICS G120 frequency converters. The vector control method was used, the effects of speed sensor presence or absence were evaluated. Also the motor temperature influence was taken into account and the proper...
We, DAIHEN Corporation, have developed a real-time power and impedance sensor that enables real-time measurement of transmitted power and coil impedance in a kW class wireless power transfer during practical power transfer. Normally, accurate power measurement is assured only for characteristic impedance in which the reflected power is zero. However, the sensor we developed enables highly accurate...
Due to their high storage capacity, low self-discharge rate and long lifetime Lithium-Ion batteries are key elements for the emerging electro-mobility and for stationary “Battery Electrical Storage Systems” (BESS). However, Li-Ion batteries are still very expensive and must be handled very carefully to exploit their features optimally. Hence, “Battery Management Systems” (BMS) have been developed...
Previous studies for measuring the high direct voltage focused on the resistive voltage divider or the hall voltage sensor. The cost of the hall voltage sensor is expensive and additional shielding method must be taken into account when using the voltage divider. In this paper, resistive voltage divider, integrated operational amplifiers and photocouplers are used cooperatively to design the 1kV DC...
Accurate, compact thermal sensors are desirable in many applications, including on-chip temperature monitoring for processors with dynamic throttling and reliability management. Modern thermal sensors are limited in either area, robustness, or accuracy. This work sidesteps strong linearity requirements for reference and PTAT elements in the sensor by performing a higher-order fitting of more relaxed...
The increase of the frequency of Earth-Low Earth Orbit satellite links leads to the development of new propagation models in order to accurately characterize the propagation channel. Space-time models are developed for tropospheric attenuation and scintillation but their validation is difficult in the absence of measured data. The verification of scintillation models can be performed worldwide against...
We demonstrated a real-time frequency measurement of CW-THz wave using a single free-running THz comb. The absolute frequency of the CW-THz wave is measured with an accuracy of 8.7∗10−12 at a rate of 10 Hz.
We report the performance results achieved for a high speed, high resolution optical FBG interrogator with a repeatability <5fm@80Hz BW and precision <200fm (p-p), designed for space applications on a launcher or atmospheric re-entry vehicle.
Microwave radiometry is a novel method for monitoring contamination levels on high voltage insulators. The microwave radiometer described measures energy emitted from the contamination layer and could provide a safe, reliable, contactless monitoring method that is effective under dry conditions. The design of the system has focused on optimizing accuracy, stability and sensitivity using a relatively...
This article aims to present a preliminary study of single point incremental sheet forming (SPIF) with warm for aluminum sheet of 1 millimeter (mm) thickness, with a propose of evaluate the contribution of adding heat for the process and even, how to reduce the processing time. For this evaluation was compared the dimensional errors between the pieces formed by the process with warm and without warm...
Thermal error accounts for a large proportion in the error sources of the machine tool. In this paper, the thermal error of a boring and milling machine tool is modeled with the output error model of timing analysis. In order to improve the prediction accuracy, Firefly algorithm is used to optimize the number of groups and the orders of output error model. A compensation system is developed based...
In order to monitor the correct operation and evaluate the energetic performance of a photovoltaic (PV) power plant, as well as to be able to compare with other PV installations, operational monitoring with appropriate measurement accuracy is necessary. Mainly due to economic reasons, in the majority of cases PV electrical parameters are measured directly by inverters. Measurements acquired with commercial...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.