scholarly journals Dissolved Oxygen Measurement in Seawater and Sensor Calibration Method

2021 ◽  
Vol 299 ◽  
pp. 02017
Author(s):  
Shun Gao ◽  
Yingying Zhang ◽  
Xiandong Feng ◽  
Da Yuan ◽  
Bingwei Wu ◽  
...  
Keyword(s):  
Dissolved Oxygen ◽  
Automatic Monitoring ◽  
Calibration Method ◽  
Oxygen Sensors ◽  
Sensor Calibration ◽  
Advantages And Disadvantages ◽  
In Situ Calibration ◽  
Laboratory Calibration ◽  
Calibration Methods ◽  
Working Principle

The development and key calibration methods of the sensors for the measurement and automatic monitoring of dissolved oxygen in seawater have always been the research focus in the field of Marine monitoring technology. This paper summarizes the measurement methods of dissolved oxygen in seawater, the working principle and advantages and disadvantages of different dissolved oxygen sensors, and the research on calibration methods of mainstream optical dissolved oxygen sensors. Especially for optical dissolved oxygen sensors with better stability, longer service life and stronger anti-interference ability, several laboratory calibration methods which have been developed and applied, as well as in situ calibration methods which are still in the research stage are analyzed.

The Calibration Method of Thermal Heat Flux Sensor Based on Wireless Sensor Networks

2014 ◽  
Vol 651-653 ◽  
pp. 538-542
Author(s):  
Xiao Shi Zheng ◽  
Guang He Cheng ◽  
Qing Long Meng ◽  
Feng Qi Hao ◽  
Xuan Cai Xu ◽  
...  
Keyword(s):  
Heat Flux ◽  
Wireless Sensor Networks ◽  
Sensor Networks ◽  
Calibration Method ◽  
Wireless Sensor ◽  
Heat Flux Sensor ◽  
Sensor Calibration ◽  
Advantages And Disadvantages ◽  
Calibration Methods ◽  
Flux Sensor

This paper analyzed the advantages and disadvantages of existing heat flux sensor calibration methods, proposed a calibration method of thermal heat flux sensor based on wireless sensor networks. Experimental results showed that the detection error was reduced from 6% to 2% after calibration. The proposed method has many advantages, such as short calibration time, accurate results, easy installation as well as batching calibration. In a word, this method is available to calibrate heat flux sensors and will have an important significance for accurate measurement of heat flux.

scholarly journals Review of Dissolved Oxygen Detection Technology: From Laboratory Analysis to Online Intelligent Detection

Sensors ◽  
2019 ◽  
Vol 19 (18) ◽  
pp. 3995 ◽  
Author(s):  
Yaoguang Wei ◽  
Yisha Jiao ◽  
Dong An ◽  
Daoliang Li ◽  
Wenshu Li ◽  
...  
Keyword(s):  
Dissolved Oxygen ◽  
Real Time ◽  
Optical Detection ◽  
Oxygen Sensors ◽  
Detection Methods ◽  
Future Research ◽  
Advantages And Disadvantages ◽  
Oxygen Detection ◽  
Detection Technology ◽  
Intelligent Technology

Dissolved oxygen is an important index to evaluate water quality, and its concentration is of great significance in industrial production, environmental monitoring, aquaculture, food production, and other fields. As its change is a continuous dynamic process, the dissolved oxygen concentration needs to be accurately measured in real time. In this paper, the principles, main applications, advantages, and disadvantages of iodometric titration, electrochemical detection, and optical detection, which are commonly used dissolved oxygen detection methods, are systematically analyzed and summarized. The detection mechanisms and materials of electrochemical and optical detection methods are examined and reviewed. Because external environmental factors readily cause interferences in dissolved oxygen detection, the traditional detection methods cannot adequately meet the accuracy, real-time, stability, and other measurement requirements; thus, it is urgent to use intelligent methods to make up for these deficiencies. This paper studies the application of intelligent technology in intelligent signal transfer processing, digital signal processing, and the real-time dynamic adaptive compensation and correction of dissolved oxygen sensors. The combined application of optical detection technology, new fluorescence-sensitive materials, and intelligent technology is the focus of future research on dissolved oxygen sensors.

scholarly journals Online Calibration Method for Current Sensors Based on GPS

Energies ◽  
2019 ◽  
Vol 12 (10) ◽  
pp. 1923
Author(s):  
Shuang Zhao ◽  
Jun Liu ◽  
Yansong Li
Keyword(s):  
Calibration Method ◽  
National Standard ◽  
Economic Losses ◽  
Current Sensor ◽  
Sensor Calibration ◽  
Gps Receiver ◽  
Angular Difference ◽  
Online Calibration ◽  
Calibration Methods ◽  
Current Sensors

At present, most sensor calibration methods are off-line calibration, which not only makes them time-consuming and laborious, but also causes considerable economic losses. Therefore, in this study, an online calibration method of current sensors is proposed to address the abovementioned issues. The principle and framework of online calibration are introduced. One of the calibration indexes is angular difference. In order to accurately verify it, data acquisition must be precisely synchronized. Therefore, a precise synchronous acquisition system based on GPS timing is proposed. The influence of ionosphere on the accuracy of GPS signal is analyzed and a new method for measuring the inherent delay of GPS receiver is proposed. The synchronous acquisition performance of the system is verified by inter-channel synchronization experiment, and the results show that the synchronization of the system is accurate. Lastly, we apply our online calibration method to the current sensor; the experimental results show that the angular difference and ratio difference meet the requirements of the national standard and the accuracy of the online calibration system can be achieved to 0.2 class, demonstrating the effectiveness of the proposed online calibration method.

The spectral calibration method for a crop nitrogen sensor

Sensor Review ◽  
2016 ◽  
Vol 36 (1) ◽  
pp. 48-56 ◽  
Author(s):  
Jun Ni ◽  
Jifei Dong ◽  
Jingchao Zhang ◽  
Fangrong Pang ◽  
Weixing Cao ◽  
...  
Keyword(s):  
Design Methodology ◽  
Measurement Accuracy ◽  
Signal To Noise Ratio ◽  
Calibration Method ◽  
Sensor Calibration ◽  
Content Type ◽  
Spectral Calibration ◽  
Calibration Methods ◽  
Detector Method ◽  
Standard Detector

Purpose – The purpose of this paper is to improve the accuracy and signal-to-noise ratio (SN) of a crop nitrogen sensor. Design/methodology/approach – The accuracy and wide adaptability of two spectral calibration methods for a crop nitrogen sensor based on standard reflectivity gray plates and standard detector, respectively, were compared. Findings – The calibration method based on standard detector could significantly improve the measurement accuracy and the SN of this crop nitrogen sensor. When compared with the method based on standard gray plates, the measurement accuracy and the SN of the crop nitrogen sensor calibrated based on the standard detector method improved by 50 and 10 per cent, respectively. Originality/value – This research analysed the calibration problems faced by the crop nitrogen sensor (type CGMD302) based on standard gray plates, and proposed a sensor calibration method based on a standard detector. Finally, the results of the two calibration methods were compared in terms of measurement accuracy and the SN of the crop nitrogen sensor.

The Comparison of Two Stereo Vision Sensor Calibration Methods

2011 ◽  
Vol 317-319 ◽  
pp. 397-400
Author(s):  
Gang Chen ◽  
Hua Chen ◽  
Yu Bo Guo ◽  
Dong Ye
Keyword(s):  
Stereo Vision ◽  
Nonlinear Distortion ◽  
Calibration Method ◽  
Sensor Calibration ◽  
Vision Sensor ◽  
Calibration Methods ◽  
Hole Model ◽  
Draw Conclusion

This paper presents and comparison two stereo vision sensor calibration methods: Volume template based calibration method and the calibration based on virtual stereo pattern. First method use a premade volume template. Second method use a group of random spatial points that are formed by an infrared LED moved with the probe of CMM. Two methods adopt an ideal pin-hole model that ignores the nonlinear distortion of the cameras. Through compare two calibratioin methods, we can draw conclusion that the first method can be applide to stereo sensor calibration in measurement field and the second method could gain higher calibrating precision.

scholarly journals Evaluation of Surface Shortwave Flux Estimates from GOES: Sensitivity to Sensor Calibration

2006 ◽  
Vol 23 (7) ◽  
pp. 927-935 ◽  
Author(s):  
Margaret M. Wonsick ◽  
Rachel T. Pinker ◽  
Wen Meng ◽  
Louis Nguyen
Keyword(s):  
Information Service ◽  
Cloud Amount ◽  
Calibration Method ◽  
Sensor Calibration ◽  
Average Difference ◽  
Ground Station ◽  
Calibration Methods ◽  
Langley Research Center ◽  
Visible Reflectance

Abstract Parameters derived from satellite observations depend on the quality of the calibration method applied to the raw satellite radiance measurements. This study investigates the sensitivity of absolute reflectance, derived cloud cover, and estimated surface shortwave (SW) downward fluxes to two different calibration methods for the visible sensor aboard the eighth Geostationary Operational Environmental Satellite (GOES-8). The first method was developed at NOAA's National Environmental Satellite, Data, and Information Service (NESDIS), and the second at the NASA Langley Research Center. Differences in visible reflectance ranged from −0.5% to 3%. The average difference in monthly mean cloud amount was ∼3%, and the average difference in monthly mean shortwave downward flux was 5 W m−2. Differences in bias and rms of the SW fluxes when evaluated against ground station measurements were less than 3 W m−2. Neither calibration method was shown to consistently outperform the other. This evaluation yields an estimate of the errors in fluxes that can be attributed to calibration.

Infra-AUV project: Metrology for low-frequency sound and vibration

2021 ◽  
Author(s):  
Lars Ceranna ◽  
Thomas Bruns ◽  
Christian Koch ◽  
Dominique Rodrigues ◽  
Stephen Robinson ◽  
...  
Keyword(s):  
Low Frequency ◽  
Monitoring Networks ◽  
Vibration Data ◽  
In Situ Calibration ◽  
Laboratory Calibration ◽  
Calibration Methods ◽  
National Measurement ◽  
Eu Project

<p>Infra-AUV is a new EU project that will establish primary measurements standards for low frequency phenomena across the fields of airborne and underwater acoustics and vibration (seismology). Combining expertise from the national measurement institutes and geophysical monitoring station operators, it will develop both high-precision laboratory-based methods of calibration and methods suitable for field use. Infra-AUV will also address requirements for reference sensors that link laboratory calibration capabilities to field requirements for measurement traceability.</p><p>To establish standards in the three technical areas, a variety of calibration principles will be employed, including extension of existing techniques such as reciprocity and optical interferometry, and development of new methods. There will also be an investigation of the potential for in-situ calibration methods, including use of both artificially generated and naturally occurring stimuli such as microseisms and microbaroms. The influence of calibration uncertainties on the determination of the measurands required by the monitoring networks will also be studied.</p><p>The project was strongly motivated by the CTBTO strategy to drive new metrology capability to underpin IMS data. The intention is to maintain interaction with stakeholders, not only in connection with the IMS, but with the broad range of users of low frequency acoustic and vibration data. </p>

scholarly journals Six-Axis Force Torque Sensor Model-Based In Situ Calibration Method and Its Impact in Floating-Based Robot Dynamic Performance

Sensors ◽  
2019 ◽  
Vol 19 (24) ◽  
pp. 5521
Author(s):  
Francisco Javier Andrade Chavez ◽  
Silvio Traversaro ◽  
Daniele Pucci
Keyword(s):  
Dynamic Performance ◽  
Calibration Method ◽  
Full Description ◽  
Temperature Drift ◽  
Model Based ◽  
Floating Base ◽  
In Situ Calibration ◽  
Calibration Methods ◽  
The Impact

A crucial part of dynamic motions is the interaction with other objects or the environment. Floating base robots have yet to perform these motions repeatably and reliably. Force torque sensors are able to provide the full description of a contact. Despite that, their use beyond a simple threshold logic is not widespread in floating base robots. Force torque sensors might change performance when mounted, which is why in situ calibration methods can improve the performance of robots by ensuring better force torque measurements. The Model-Based in situ calibration method with temperature compensation has shown promising results in improving FT sensor measurements. There are two main goals for this paper. The first is to facilitate the use and understanding of the method by providing guidelines that show their usefulness through experimental results. Then the impact of having better FT measurements with no temperature drift are demonstrated by proving that the offset estimated with this method is still useful days and even a month from the time of estimation. The effect of this is showcased by comparing the sensor response with different offsets simultaneously during real robot experiments. Furthermore, quantitative results of the improvement in dynamic behaviors due to the in situ calibration are shown. Finally, we show how using better FT measurements as feedback in low and high level controllers can impact the performance of floating base robots during dynamic motions. Experiments were performed on the floating base robot iCub.

Development of a Non-Invasive Calibration Method for Ocular Tactile Tonometry

2013 ◽  
Author(s):  
Eniko T. Enikov ◽  
Péter P. Polyvás
Keyword(s):  
Calibration Method ◽  
Calibration Procedure ◽  
Superior Performance ◽  
Sensor Calibration ◽  
Ann Model ◽  
Element Analysis ◽  
Reduced Order ◽  
Non Invasive ◽  
Calibration Methods ◽  
Artificial Neural Network Ann

This article describes a novel method of indirect estimation of intra-ocular pressure using tactile sensors. Two sensor calibration methods have been demonstrated: an artificial neural network (ANN) model and a phenomenological reduced-parameter model based on finite element analysis. The ANN method showed superior performance with an accuracy of +/− 0.7 mmHg, while the reduced order method showed an accuracy of +/− 3.11 mmHg. The latter method however allows calibration of the tactile tonometer from a single pressure measurement if the geometry of the probes is known and satisfying certain solvability conditions. The ANN method was demonstrated using experiment data, while the reduced-order model was tested numerically. Due to its indirect and non-invasive nature, the proposed tactile measurement method can be used in the development of a self-administered home tonometer for management of glaucoma, however the presence of an eye lid might require modification of the calibration procedure outlined here.

scholarly journals An overview of in-orbit radiometric calibration of typical satellite sensors

2015 ◽  
Vol XL-7/W4 ◽  
pp. 235-240 ◽  
Author(s):  
G. Q. Zhou ◽  
C. Y. Li ◽  
T. Yue ◽  
L. J. Jiang ◽  
N. Liu ◽  
...  
Keyword(s):  
Near Infrared ◽  
Calibration Method ◽  
Radiometric Calibration ◽  
Infrared Band ◽  
Advantages And Disadvantages ◽  
The Past ◽  
Calibration Methods ◽  
Satellite Sensors ◽  
Similarities And Differences ◽  
Typical Satellite

This paper reviews the development of in-orbit radiometric calibration methods in the past 40 years. It summarizes the development of in-orbit radiometric calibration technology of typical satellite sensors in the visible/near-infrared bands and the thermal infrared band. Focuses on the visible/near-infrared bands radiometric calibration method including: Lamp calibration and solar radiationbased calibration. Summarizes the calibration technology of Landsat series satellite sensors including MSS, TM, ETM+, OLI, TIRS; SPOT series satellite sensors including HRV, HRS. In addition to the above sensors, there are also summarizing ALI which was equipped on EO-1, IRMSS which was equipped on CBERS series satellite. Comparing the in-orbit radiometric calibration technology of different periods but the same type satellite sensors analyzes the similarities and differences of calibration technology. Meanwhile summarizes the in-orbit radiometric calibration technology in the same periods but different country satellite sensors advantages and disadvantages of calibration technology.

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