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LIDAR Systems for Atmosphere Monitoring
Published in Ghenadii Korotcenkov, Handbook of Humidity Measurement, 2018
The advantages of DIAL measurements are their relatively high spatial resolution, high measurement specificity, lack of dependence on external light sources, and relatively simple inversion methods compared to retrieval methods used in passive remote sensing (Measures 1984; Grant 1991). With the DIAL method, LIDAR measurements can be made during day or night and in between and up to cloudy regions in the atmosphere. The DIAL method provides a self-calibrated absolute water vapor measurement capability. The DIAL technique can be used to directly obtain the concentration profile of water vapor using the LIDAR signals and Δσ. The advantage of the DIAL method is also that in addition to measuring gas concentration profiles, high spatial resolution aerosol backscattering distributions are simultaneously can be obtained as part of the DIAL measurement using the off-line LIDAR signals. The vertical and/or horizontal resolution can be adjusted in the DIAL analysis by changing how the high-resolution LIDAR data are averaged.
Laboratory testing of soils
Published in John Atkinson, The Mechanics of Soils and Foundations, 2017
The last of these is simply a matter of sound understanding of the basic theories involved, rather than blindly following a cookery book approach. The purpose of this book is to develop this sound understanding. The first two are largely a matter of care and attention and experience. In assessing the quality of a set of test results it is essential to distinguish very carefully and clearly between the accuracy and the resolution of the instruments. The resolution (or precision) of an observation is the smallest increment that can be discerned, while the accuracy is the limit within which you can be absolutely confident of the data. For a typical dial gauge measuring small displacements, the resolution and accuracy are both about 0.001 mm, but the resolution and accuracy of electronic instruments are often very different.
Characterization and Modeling of PWB Warpage and Its Effect on LGA Separable Interconnects
Published in Juan Cepeda-Rizo, Jeremiah Gayle, Joshua Ravich, Thermal and Structural Electronic Packaging Analysis for Space and Extreme Environments, 2021
Juan Cepeda-Rizo, Jeremiah Gayle, Joshua Ravich
This is performed by internal inspection department on a sample-lot basis and is the only warpage assessment technique employed to determine adherence to [2]. The technique involves laying the panel on a flat granite datum surface and using a pin gauge at designated areas to measure the panel profile. It is a quick way to obtain a warpage value that can be used to accept or reject material base from a specification. The dial indicator has an accuracy of ±.0001 inch.
Influence of multi-walled carbon nanotubes on creep behavior of adhesively bonded joints subjected to elevated temperatures
Published in The Journal of Adhesion, 2019
Hadi Khoramishad, Roya Sadat Ashofteh
The creep tests were performed at the same time and under the same conditions on three specimens for each load and temperature level. It should be mentioned that the performance of the test setup was first well calibrated based on some basic tests. The creep test apparatus consisted of several units including a loading mechanism, a heating system and a displacement measurement system. The creep load was applied using an electro-pneumatic system coupled with an S-type load-cell. The load-cell was calibrated using several standard gauge loads. The thermometer was checked using a calibrated portable thermometer to insure correct temperature reading and controlling. Moreover, the measuring dial-gauges were calibrated using standard gauge blocks.
Experimental and numerical study on lateral and longitudinal resistance of ballasted track with nailed sleeper
Published in International Journal of Rail Transportation, 2022
Yunlong Guo, Lu Zong, Valeri Markine, Xinyu Wang, Guoqing Jing
The facilities applied for the SSPTs include the hydraulic jack, dial indicator, pressure sensor and data acquisition system. The maximum loading of hydraulic jack is 20 ton, which is sufficient to provide enough force to move the sleeper until the peak resistance value. The actuator stroke can travel at most 10 cm. The travelling distance is enough for reaching the required maximum sleeper displacement. The dial indicator precision is 0.001 mm, and can measure distances at most 30 mm. The pressure sensor can measure the loading in the range of 0 ~ 15 ton, and the data acquisition system is used to collect the force data from pressure sensor.
Analysis of degradation process of a railway steel bridge in the final period of its operation
Published in Structure and Infrastructure Engineering, 2023
Ryszard Chmielewski, Paweł Muzolf
The deformation of the structure was taken into account by measuring its deflection under the influence of the characteristic loads from the rolling stock. The permanent displacement of the span structure and the effect of settlement of the bridge supports were neglected. The absolute value of the deflection of the spans (in the middle of its span) was measured, without taking into account the settlement of the supports. Measurements were made with analogue dial sensors with an accuracy of 0.01 mm. The bridge was subjected to a moving load, which was the fully tanked ET-22 locomotive. The theoretical value of the structure deflection under applied load (without taking into consideration the corrosion damage) should be However, the measured mean value of span deflection from the side of the overloaded girder was: The cross-sections corrosion loss of the girders, and thus the reduction of their moment of inertia, was responsible for the increase in the measured deflection in relation to the theoretical values. The spar overload coefficient, determined on the basis of the eccentric track misalignment to the bridge structure (the lack of collinearity between the track axis and the bridge axis) was 4.23%. The relative difference between the calculated deflection and the measured deflection was 12.69%. Taking into account the influence of the overload, the reduction in the stiffness of the span structure was 8.46%. The decrease in the moment of inertia of the girder's section determined in the numerical model is 7.58% (see Table 2 in Chapter 4). The difference in the drop in girder stiffness between the value obtained from the measurement of the deflection of the span without taking into account the settlement of the supports and the value determined in the numerical model was only 0.88%.