The impact of stiffness increasing in construction of tire measuring device to measured results

The article analyzes the influence of the construction stiffness of the measuring device and its effort to the resulting measured results. The article deals with the possibility of increasing the accuracy of measurement and at the same time reducing the measurement deviation on the measuring device by increasing the rigidity of the structure of the device. In the introduction, the article describes the stiffness, errors and analyzes the possibilities of increasing the accuracy of measurement on the measuring device and examines the causes of measurement deviations. In the next part, the article offers the possibilities of increasing the rigidity and strength of the measuring device. In the practical part, the structural modification of the device increasing the overall rigidity and strength of the structure is presented. In the practical part we made a simulation of old device frame and modified frame. In the last part, the article compares the results of measurements before the structural modification and after the structural modification of the increase in stiffness.

Lateral resolution limit of laser Doppler vibrometer microscopes for the measurement of surface acoustic waves

The lateral or transverse resolution of single-point interferometers for vibration measurement is especially critical for microelectromechanical systems (MEMS) vibrating up to the gigahertz range. In this regime, the acoustic wavelengths are typically in the range of the size of the laser focus. Thus, a successful vibration measurement requires distinct knowledge about the lateral resolution limit and its dependencies with instrumentation parameters. In this paper, we derive an analytic approximation formula, which allows for estimation of the systematic measurement deviation of the vibration amplitude and, thus, a definition of the lateral resolution limit of single-point interferometers for vibration measurement. Further, a compensation and an optimum numerical aperture are proposed the reduce the measurement deviation. For this, the model includes a laser-interferometer microscope of Mach-Zehnder type with Gaussian laser beams considering the Gouy effect and wavefront curvature. As a measurement scenario, an unidirectional surface acoustic wave (SAW) is regarded. The theoretic findings have been validated in the experiment with a representative vibration measurement on a SAW filter at $$433\,{\mathrm {MHz}}$$ 433 MHz with our heterodyne laser-Doppler interferometer with offset-locked semiconductor lasers. The provided formulas help instrument designers and users to choose suitable instrument parameters, especially the numerical aperture of the utilized microscope objective.

A Straightness Error Compensation System for Topography Measurement Based on Thin Film Interferometry

Straightness error compensation is a critical process for high-accuracy topography measurement. In this paper, a straightness measurement system was presented based on the principle of fringe interferometry. This system consisted of a moving optical flat and a stationary prism placed close to each other. With a properly aligned incident light beam, the air wedge between the optical flat and the prism would generate the interferogram, which was captured by a digital camera. When the optical flat was moving with the motion stage, the variation in air wedge thickness due to the imperfect straightness of the guideway would lead to a phase shift of the interferogram. The phase shift could be calculated, and the air wedge thickness could be measured accordingly using the image processing algorithm developed in-house. This air wedge thickness was directly correlated with the straightness of the motion stage. A commercial confocal sensor was employed as the reference system. Experimental results showed that the repeatability of the proposed film interferometer represented by σ was within 25 nm. The measurement deviation between the film interferometer and the reference confocal sensor was within ±0.1 µm. Compared with other interferometric straightness measurement technologies, the presented methodology was featured by a simplified design and good environment robustness. The presented system could potentially be able to measure straightness in both linear and angular values, and the main focus was to analyze its linear value measurement capability.

Effect analysis of surface metal layer on step height standard

In order to improve the measurement accuracy of the step height measuring instrument, a semiconductor process was used to prepare the step height standard for calibrating the instrument. Aiming at the problem of deviation in the white light interferometer measuring step height standard, the cause of the measurement deviation was theoretically analyzed, combining the optical theory and the principle of instrument. In addition, referring to the semiconductor sputtering process, a method of sputtering metal layer on the surface of the step structure was proposed, and a set of universal step height standards with a nominal value of [Formula: see text] nm were developed for the step height measuring instrument. Finally, the step height standards with the sputtered metal layer were compared and measured, using the white light interferometer and nanometer measuring machine (NMM). The measurement error of the white light interferometer can be effectively controlled within 1%, which is beneficial to verify the measurement capability of the step height measuring instrument.

INFLUENCE OF MEASURING DEVIATIONS OF THE COMPONENTS OF LAYERED WALLS ON THEIR DURABILITY

The subject of the article is the impact of measurement deviations of three-layer walls on the durability of these walls in buildings erected according to the OWT-67 / N system. This problem mainly concerns the external facade texture layer, which, apart from its own weight load, is exposed to the destructive influence of external factors, which include wind suction load and temperature load. The measurement deviation regarding the texture layer is the varied thickness of the board. Other diverse components that affect the fusion of the texture layer with the insulation layer and the construction layer are: diameter of rods hangers, coating thickness of rods hangers and diameter of rods anchoring hangers. Based on these measurements, a polynomial model was created based on an experimental plan that evaluated the durability of the layered wall.

INFLUENCE OF MEASURING DEVIATIONS OF THE COMPONENTS OF LAYERED WALLS ON THEIR DURABILITY

The subject of the article is the impact of measurement deviations of three-layer walls on the durability of these walls in buildings erected according to the OWT-67 / N system. This problem mainly concerns the external facade texture layer, which, apart from its own weight load, is exposed to the destructive influence of external factors, which include wind suction load and temperature load. The measurement deviation regarding the texture layer is the varied thickness of the board. Other diverse components that affect the fusion of the texture layer with the insulation layer and the construction layer are: diameter of rods hangers, coating thickness of rods hangers and diameter of rods anchoring hangers. Based on these measurements, a polynomial model was created based on an experimental plan that evaluated the durability of the layered wall.

A Fast-Response Calorimeter with Dynamic Corrections for Transient Heat Transfer Measurements

Robust fast-response transient calorimeters with novel calorimeter elements have attracted the attention of researchers as new synthetic materials have been developed. This sensor uses diamonds as the calorimeter element, and a platinum film resistance is sputtered on the back to measure the temperature. The surface heat flux is obtained based on the calorimetric principle. The sensor has the advantages of high sensitivity and not being prone to erosion. However, non-ideal conditions, such as heat dissipation from the calorimeter element to the surroundings, can lead to measurement deviation and result in challenges for sensor miniaturization. In this study, a novel transient calorimeter (NTC) with two different sizes was developed using air or epoxy as the back-filling material. Numerical simulations were conducted to explain the complex heat exchange between the calorimeter element and its surroundings, which showed that it deviated from the assumption of an ideal calorimeter sensor. Accordingly, a dynamic correction method was proposed to compensate for the energy loss from the backside of the calorimeter element. The numerical results showed that the dynamic correction method significantly improved the measurement deviation, and the relative error was within 2.3% if the test time was smaller than 12 ms in the simulated cases. Detonation shock tunnel experiments confirmed the results of the dynamic correction method and demonstrated a practical method to obtain the dynamic correction coefficient. The accuracy and feasibility of the dynamic correction method were verified in a single detonation shock tunnel and under shock tube conditions. The NTC calorimeter exhibited good repeatability in all experiments.

Acoustic Roughness Measurement of Railhead Surface Using an Optimal Sensor Batch Algorithm

Contact and friction between wheel and rail during train operation is the main cause of the rolling noise for which railways are known. Therefore, it is necessary to accurately measure the surface roughness of wheels and rails to monitor railway noise and predict noise around tracks. Conventional systems developed to measure surface roughness have large deviations in measured values or low repeatability. The recently developed automatic mobile measurement platform known as Auto Rail Checker (ARCer) uses three displacement sensors to reduce measurement deviation and increase the accuracy of existing systems. This paper proposes enhancing the chord offset synchronization algorithm applied to the existing ARCer for high measurement precision with only two displacement sensors. As a result, when the two sensor-based measurement algorithm was applied, the spectrum level at λ = 0.314 m, the wavelength amplification associated with wheel diameter, was reduced to at least 6 dB in comparison with that of the three sensors based algorithm. We also verified the accuracy of the proposed batch algorithm through a field test on an operating rail track with a corrugated rail surface.