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Development of precise barometric sensor
Bebej, Rastislav ; Králík, Jan (referee) ; Řeřucha,, Šimon (advisor)
This thesis deals with the development of an electronic module for absolute air pressure measurement. The device is to be used in interferometry in length metrology, where it is necessary to determine the value of atmospheric pressure with high accuracy. The thesis includes a research focused on the selection of suitable pressure sensors for this purpose and the selection of supporting components. The thesis also deals with the design of the circuit design and the printed circuit board. The module communicates with the device network via CAN bus, using the CANopen protocol. The device has been thoroughly tested with a reference barometer and in a controlled environment of a temperature chamber. The aim of these measurements was to determine the noise characteristics and to assess the proposed filtering using an IIR filter. Based on the calibration with a certified barometer, the device is supplemented with offset compensation, temperature influence compensation and linearly dependent pressure deviation compensation.
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Characterization and elimination of thermomechanical effects in interferometric length measurement
Řeřucha, Šimon ; Holá, Miroslava ; Lazar, Josef ; Mikel, Břetislav ; Číp, Ondřej
Continuous efforts to develop dimensional measurements at both the nano- and macro-scale continue to present challenges in extending high-precision measurement procedures from the well-controlled experimental environment of a typically single measurement cycle to a constant-load production environment. In the field of laser interferometry, which is both a cornerstone of length metrology in general and an essential part of nanometrology, we have focused on long-term measurement stability (so-called zero-drift) in measurement scenarios and applications based on (mostly laser) interferometry. A well-characterized and compensated measurement zero-drift in such applications becomes more important both with applications in less controlled environments and with increasing measurement timeframes, such as long scans in microscopic nanometrology, long exposures in electron lithography, or interferometric reference calibrations with a larger number of calibration points or repetitions. The goal of the current research effort is to comprehensively investigate error effects and contributions to measurement uncertainty related to zero-drift in laser interferometry-based applications, with a particular focus on temperature effects (as these typically appear to be the dominant contribution) and approaches to suppress them. This effort involves several complementary directions.
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Advanced Laser Measuring Systems in Nanometrology
Lazar, Josef ; Hrabina, Jan ; Holá, Miroslava ; Vychodil, M.
We present a development of a nanometrology system combining local probe microscopy and precise positioning and measuring in the nanoscale. The positioning operates in short range with a focus on precision; displacement measurement controls the sample stage in six degrees of freedom with high-resolution interferometry. The system is designed to operate as a national standard for nanometrology. The contribution presents collaborative work with Meopta company.
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