scholarly journals Evaluation of LIDAR and Camera External Reference Calibration Methods

2021 ◽  
Vol 33 (12) ◽  
pp. 1
Author(s):  
Yao Fu ◽  
Dean Luo ◽  
He Huang ◽  
Yizhou Xue ◽  
Tong Yin
Keyword(s):  
External Reference ◽  
Calibration Methods

100 KV Scanning Microscope

1972 ◽  
Vol 30 ◽  
pp. 472-473 ◽  
Author(s):  
A. V. Crewe ◽  
M. W. Retsky
Keyword(s):  
High Voltage ◽  
Voltage Divider ◽  
Electron Gun ◽  
Objective Lens ◽  
Parallel Beam ◽  
Emission Point ◽  
Error Amplifier ◽  
External Reference ◽  
Scanning Transmission ◽  
Transmission Microscope

A 100 kv scanning transmission microscope has been built. Briefly, the design is as follows: The electron gun consists of a field emission point and a 3 cm Butler gun. The beam has a crossover outside the gun and is collimated by a condenser lens.The parallel beam passes through a defining aperture and is focused by the objective lens onto the specimen. The elastic electrons are detected by two annular detectors, each subtending a different angle, and the unscattered and inelastic electrons are collected by a third detector. The spectrometer that will separate the inelastic and unscattered electrons has not yet been built.The lens current supplies are stable to within one part per million per hour and have been described elsewhere.The high voltage is also stable to 1 ppm/hr. It consists of the raw supply from a 100 kv Spellman power supply controlled by an external reference voltage, high voltage divider, and error amplifier.

Variability in the establishment of an external reference point for central venous pressure measurement in children

2006 ◽  
Vol 0 (0) ◽  
Author(s):  
Aline S. C. Belela ◽  
Mavilde L. G. Pedreira ◽  
Maria Angélica S. Peterlini ◽  
Denise M. Kusahara ◽  
Werther B. Carvalho ◽  
...  
Keyword(s):  
Central Venous Pressure ◽  
Pressure Measurement ◽  
Reference Point ◽  
Venous Pressure ◽  
Central Venous ◽  
External Reference

scholarly journals Space Charge Effects in Noble-Liquid Calorimeters and Time Projection Chambers

Instruments ◽  
2021 ◽  
Vol 5 (1) ◽  
pp. 9
Author(s):  
Sandro Palestini
Keyword(s):  
Space Charge ◽  
Scaling Laws ◽  
Relative Size ◽  
Design Solution ◽  
Space Charge Effects ◽  
Charge Effects ◽  
Time Projection Chambers ◽  
Drift Length ◽  
Calibration Methods ◽  
Time Projection

The subject of space charge in ionization detectors is reviewed, showing how the observations and the formalism used to describe the effects have evolved, starting with applications to calorimeters and reaching recent, large time-projection chambers. General scaling laws, and different ways to present and model the effects are presented. The relations between space-charge effects and the boundary conditions imposed on the side faces of the detector are discussed, together with a design solution that mitigates some of the effects. The implications of the relative size of drift length and transverse detector size are illustrated. Calibration methods are briefly discussed.

scholarly journals Calibration and Uncertainty Estimation for Water Content Measurement in Solids

2021 ◽  
Vol 42 (3) ◽  
Author(s):  
Rudolf Aro ◽  
Mohamed Wajdi Ben Ayoub ◽  
Ivo Leito ◽  
Éric Georgin ◽  
Benoit Savanier
Keyword(s):  
Water Vapor ◽  
Water Content ◽  
Software Tool ◽  
Uncertainty Estimation ◽  
Multiple Point ◽  
Content Measurement ◽  
Analysis Technique ◽  
Calibration Methods ◽  
Vapor Analysis ◽  
Secondary Methods

AbstractIn the field of water content measurement, the calibration of coulometric methods (e.g., coulometric Karl Fischer titration or evolved water vapor analysis) is often overlooked. However, as coulometric water content measurement methods are used to calibrate secondary methods, their results must be obtained with the highest degree of confidence. The utility of calibrating such instruments has been recently demonstrated. Both single and multiple point calibration methods have been suggested. This work compares these calibration methods for the evolved water vapor analysis technique. Two uncertainty estimation approaches (Kragten’s spreadsheet and M-CARE software tool) were compared as well, both based on the ISO GUM method.

scholarly journals A Multi Camera and Multi Laser Calibration Method for 3D Reconstruction of Revolution Parts

Sensors ◽  
2021 ◽  
Vol 21 (3) ◽  
pp. 765
Author(s):  
Hugo Álvarez ◽  
Marcos Alonso ◽  
Jairo R. Sánchez ◽  
Alberto Izaguirre
Keyword(s):  
3D Reconstruction ◽  
Calibration Method ◽  
Laser Plane ◽  
Calibration Methods ◽  
Laser Calibration ◽  
Calibration Object ◽  
Focus Plane ◽  
Chessboard Pattern ◽  
Line Patterns

This paper describes a method for calibrating multi camera and multi laser 3D triangulation systems, particularly for those using Scheimpflug adapters. Under this configuration, the focus plane of the camera is located at the laser plane, making it difficult to use traditional calibration methods, such as chessboard pattern-based strategies. Our method uses a conical calibration object whose intersections with the laser planes generate stepped line patterns that can be used to calculate the camera-laser homographies. The calibration object has been designed to calibrate scanners for revolving surfaces, but it can be easily extended to linear setups. The experiments carried out show that the proposed system has a precision of 0.1 mm.

scholarly journals Recent Progress of Fluxgate Magnetic Sensors: Basic Research and Application

Sensors ◽  
2021 ◽  
Vol 21 (4) ◽  
pp. 1500
Author(s):  
Songrui Wei ◽  
Xiaoqi Liao ◽  
Han Zhang ◽  
Jianhua Pang ◽  
Yan Zhou
Keyword(s):  
Recent Progress ◽  
Electronic Devices ◽  
Basic Research ◽  
Research Direction ◽  
Magnetic Sensor ◽  
Magnetic Sensors ◽  
Future Research ◽  
Calibration Methods ◽  
Wearable Electronic ◽  
Wearable Electronic Devices

Fluxgate magnetic sensors are especially important in detecting weak magnetic fields. The mechanism of a fluxgate magnetic sensor is based on Faraday’s law of electromagnetic induction. The structure of a fluxgate magnetic sensor mainly consists of excitation windings, core and sensing windings, similar to the structure of a transformer. To date, they have been applied to many fields such as geophysics and astro-observations, wearable electronic devices and non-destructive testing. In this review, we report the recent progress in both the basic research and applications of fluxgate magnetic sensors, especially in the past two years. Regarding the basic research, we focus on the progress in lowering the noise, better calibration methods and increasing the sensitivity. Concerning applications, we introduce recent work about fluxgate magnetometers on spacecraft, unmanned aerial vehicles, wearable electronic devices and defect detection in coiled tubing. Based on the above work, we hope that we can have a clearer prospect about the future research direction of fluxgate magnetic sensor.

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