scholarly journals Creation of Pulse Method for Measurement of Ultrasonic Velocity with High Accuracy

2021 ◽  
Vol 19 (2) ◽  
pp. 13
Author(s):  
V V Muravyov ◽  
D V Zlobin ◽  
T I Zemskov ◽  
G V Bezruchenkov ◽  
V V Syaktereva
Keyword(s):  
Ultrasonic Velocity ◽  
Pulse Method ◽  
High Accuracy

В статье обсуждаются способы высокоточного определения скорости ультразвука в твердых материалах. Описана методика проведения точных измерений временных интервалов ультразвуковых импульсов, приведена блок-схема экспериментальной установки. Установка построена на широкодоступных компонентах, возможна ее простая модернизация. Предложено использование датчика на основе сегнетоэлектрического полимера поливинилиденфторида в качестве источника излучения и приема продольных волн. В качестве объектов контроля используются концевые меры длины и ступенчатый образец из стали, изготовленный с использованием плоскошлифовального станка. Представлены результаты определения скорости, подтвержденные многократными измерениями на ступенчатом объекте с разницей по толщине ступеней 10 мкм. Проведен эксперимент при изменяемой температуре образцов концевых мер длины, подтверждающий точность измерений и разницу в рассчитанной скорости, свидетельствующий о разном структурном составе объектов. Определен химический состав образцов концевых мер длины с использованием рентгено-флуоресцентного анализатора. Представлен график зависимости плотности объектов от скорости ультразвука. Описаны погрешности измерений, способы их расчета, в частности временная задержка при использовании пленочного датчика. Абсолютная погрешность определения скорости ультразвуковых продольных волн не превышает 2 м/с, что позволяет фиксировать крайне малые отклонения скорости ультразвука в образцах.

Design and Implementation of Ultrasonic Ranging System

2012 ◽  
Vol 239-240 ◽  
pp. 37-41
Author(s):  
Cui Li Mao ◽  
Er Hua Wang ◽  
Hong Qi Lin
Keyword(s):  
Real Time ◽  
High Precision ◽  
Temperature Compensation ◽  
Small Volume ◽  
Pulse Method ◽  
High Accuracy ◽  
Reservoir Level ◽  
Reliable Operation ◽  
Design And Implementation ◽  
Ultrasonic Ranging

A real-time and high precision ultrasonic ranging method is proposed here. Ultrasonic ranging system based on MCU was established, which is composed of MCU, ultrasonic sending and receiving circuit, temperature compensate circuit, alarm, key and display circuit. Counting pulse method was used to measure the ultrasonic transmission time, and then the distance is calculated. In order to improve the ranging accuracy, temperature compensation was used in this system. Preliminary experiment showed that the system meet the requirements. This system has advantages such as low price, small volume, reliable operation, high accuracy, and can be employed in car backing, obstacle avoiding of robots, industrial logging, reservoir level measuring etc.

A New 1,000 kV Electron Microscope

1967 ◽  
Vol 25 ◽  
pp. 260-261
Author(s):  
M. Nishigaki ◽  
S. Katagiri ◽  
H. Kimura ◽  
B. Tadano
Keyword(s):  
Electron Microscope ◽  
High Voltage ◽  
Basic Research ◽  
Chromatic Aberration ◽  
High Accuracy ◽  
Biological Specimen ◽  
Voltage Electron ◽  
High Voltage Electron Microscope ◽  
High Voltage Electron

The high voltage electron microscope has many advantageous features in comparison with the ordinary electron microscope. They are a higher penetrating efficiency of the electron, low chromatic aberration, high accuracy of the selected area diffraction and so on. Thus, the high voltage electron microscope becomes an indispensable instrument for the metallurgical, polymer and biological specimen studies. The application of the instrument involves today not only basic research but routine survey in the various fields. Particularly for the latter purpose, the performance, maintenance and reliability of the microscope should be same as those of commercial ones. The authors completed a 500 kV electron microscope in 1964 and a 1,000 kV one in 1966 taking these points into consideration. The construction of our 1,000 kV electron microscope is described below.

Application Of BIM-Technology In The Restoration Of Buildings

2020 ◽  
pp. 42-48
Keyword(s):  
Chinese Communist Party ◽  
Laser Scanning ◽  
High Accuracy ◽  
Information Environment ◽  
Information Modeling ◽  
Structural Scheme ◽  
Traditional Design ◽  
Information Interaction ◽  
Heritage Buildings ◽  
Effective Organization

The paper describes the main trends in the development of BIM technologies in the field of restoration and reconstruction of historical and cultural heritage buildings. The practical part of the paper presents the experience in using information modeling technologies when restoring the building, where the VI Congress of the Chinese Communist Party in Moscow took place. The use of laser scanning technologies made it possible to reproduce with high accuracy in the information model the original appearance of the building using Autodesk RevitR software. It is shown, how the use of information modeling technologies affects the duration of restoration process, taking into account the calculation of the structural scheme and bearing structures of the building, ensuring the identity of the decoration and the effective organization of electromechanical installation. Operating in a single BIM information environment makes it possible to continuously obtain reliable information on the project, which provides more effective information interaction and communication of participants compared to using traditional design methods.

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