Visible spectroscopy calibration transfer model in determining pH of Sala mangoes

Yahaya, Ommi Kalsom Mardziah; MatJafri, M. Z.; Aziz, Azlan Abdul; Omar, Ahmad

doi:10.1088/1748-0221/10/05/t05002

Cited by 12 publications

(8 citation statements)

References 41 publications

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“…Yahaya et al (2015) found that the spectral model established by the QE65000 spectrometer could be transferred to the FieldSpec 3 spectrometer more easily and in a better way than another portable spectrometer, suggesting that the two spectrometers could be replaced by each other [ 27 ]. In this study, QEPro and FieldSpec 4 were the upgraded spectrometers of QE65000 and FieldSpec 3, respectively, suggesting that QEPro and FieldSpec 4 also could replace each other.…”

Section: Discussionmentioning

confidence: 99%

A Method to Evaluate Spectral Analysis by Spectroscopy

Liu

Fan

Qiu

et al. 2022

Sensors

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Visible and near infrared spectroscopy has been widely used to develop a method for rapidly determining organic carbon in soils or sediments (SOC). Most of these studies concentrated on how to establish a good spectral model but ignored how to evaluate the method, such as the use of detection range (max and min), resolution and error for SOC spectral analysis. Here, we proposed a method to evaluate the spectral analysis of SOC. Using 96 sediments sampled in the Yellow Sea and Bohai Sea, China, we established three spectral models of SOC after collecting their spectral reflectance by Agilent Cary 5000, ASD FieldSpec 4 and Ocean Optics QEPro, respectively. For both the calibration set and validation set in each spectrometer, the predicted SOC concentrations followed a distribution curve (function), in which the x-axis was the SOC concentrations. Using these curves, we developed these four technical parameters. The detection ranges were the SOC concentrations where the curve was near to or crossing with the lateral axis, while the detection resolution was the average difference between the two neighboring SOC concentrations. The detection errors were the differences between the predicted SOC and the measured SOC. The results show that these technical parameters were better in the bench-top spectrometer (Cary 5000) than those in the portable spectrometers when analyzing the same samples. For the portable spectrometers, QEPro had a broader detection range and more consistent detection error than FieldSpec 4, suggesting that the low-cost QEPro performed as well as the high-cost FieldSpec 4. This study provides a good example for evaluating spectral analysis by spectroscopy, which can support the development of the spectral method.

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Section: Discussionmentioning

confidence: 99%

A Method to Evaluate Spectral Analysis by Spectroscopy

Liu

Fan

Qiu

et al. 2022

Sensors

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“…The coefficient of determination, R 2 and root mean square error (RMSE) will represent the accuracy of the generated linear line while its slope will represent the influence of UVA-LED wavelength in defining the discoloration magnitude or sensitivity of the film. R 2 and RMSE is a widely recognized statistical tool in representing the accuracy of the measurement technique (Yahaya et al, 2015;Zhao & Wu, 2018 ; Sun, Li & Niu, 2018): Area under the curve5…”

Section: Methodsmentioning

confidence: 99%

EBT3-based dosimeter in characterizing UVA–LEDs with lambertian radiation pattern

Omar

Chiong

Tan

et al. 2019

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Purpose This paper aims to propose an area under the curve model to represent ultraviolet (UV) exposure doses on EBT3 films (in mJ/cm2). The model was developed on a cross-section of the exposed films using visible absorbance method. Ultraviolet–A light emitting diodes (UVA–LEDs) with 20° and 60° half angle with distinctive peak emission wavelengths between 365 to 405 nm are used in this experiment. No similar experimental setup or findings have been reported thus far, though the various application of EBT3 for the measurement of solar UV (A + B) have been published since EBT3 is commercially available. Design/methodology/approach Two sets of UVA–LEDs were used as the UV radiation source in the experiment. The first set contains of four 5 mm low power UVA–LEDs with the 20° half angle and peak emission wavelength at 365, 375, 385 and 400 nm. The second set contains of five surface mount high power UVA–LEDs with the 60° half angle and peak emission wavelength at 365, 375, 385, 305 and 400 nm. The illumination setup for the two sets of LEDs is different between each other to obtain sufficient dose distribution on the films for spectroscopy analysis. This is due to the different illumination angle and irradiance intensity by each set of LEDs. Findings UV–LED with a peak emission of 365, 375 and 385 nm able to produce UV doses accurately measurable using EBT3 films, UVA–LEDs with peak emission at 395 nm and above produced much lower accuracy with R2. From both set of LEDs, it can be concluded that peak emission wavelength of UVA–LED does influence the discoloration of the films. Shorter wavelength (higher energy) of UVA–LEDs discolors EBT3 films much intense compared to longer wavelength for a given UV dose exposure. Originality/value Despite various practical applicability and advantages of UV–LEDs, there are still no standard methods in measuring UV–LED radiation output. The proposed approach not only allows us to obtain the dose of UV–LED, where the sensitivity of measurement is wavelength (energy) depended but also allows us to visually observe the illumination pattern of invisible UV radiation through the application of EBT3 films.

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“…Currently, studies are concentrated on the similar questions for the same samples derived from different instruments, measurement conditions, or other aspects (called calibration transfer) [15][16][17][18][19]. Many algorithms have successfully resolved these calibration transfer, such as direct standardization (DS) [20,21], piecewise direct standardization (PDS) [22,23], orthogonal signal method (OSC) [24,25], wavelet transform (WT) algorithm [26,27], and canonical correlation analysis(CCA) [28,29].…”

Section: Introductionmentioning

confidence: 99%

Calibration Transfer of Soil Total Carbon and Total Nitrogen between Two Different Types of Soils Based on Visible-Near-Infrared Reflectance Spectroscopy

Liu

et al. 2018

Journal of Spectroscopy

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Although visible-near-infrared spectroscopy can rapidly and accurately determine soil nutrients without sample destruction, some problems remain unresolved, such as the mismatch of the established spectral model with different types of samples, limiting the wide application of this technology. Here, we took riverside and mountain soils as examples to explore the calibration transfer between two different types of soils by the WMPDS-S/B algorithm (wavelet multiscale piecewise direct standardization combined with Slope/Bias correction method) and by adding new samples. e predicted TN and TC concentrations improved significantly after being transformed. Compared with adding new samples, the WMPDS-S/B algorithm obtained more accurate results. e average relative errors dropped from 440.2% (without transformation) to approximately 6% for TN and from 342.0% to approximately 7% for TC. e maximum relative errors were reduced from 538.1% to less than 20% for TN and from 403.7% to less than 20% for TC. e RMSEP decreased from 2.42 to approximately 0.04 for TN and from 15.74 to approximately 0.4 for TC. e WMPDS-S/B algorithm had advantages in selecting fewer known samples and obtaining better prediction results. In contrast to past studies, which resolved the calibration transfer between different spectrometers and the measurement environment for the same samples, our study resolved the calibration transfer between different types of samples under the same spectrometer and the measurement environment. e former could only be used for correction among instruments, while the latter fundamentally solved the problem of model sharing across different samples.

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Visible spectroscopy calibration transfer model in determining pH of Sala mangoes

Cited by 12 publications

References 41 publications

A Method to Evaluate Spectral Analysis by Spectroscopy

A Method to Evaluate Spectral Analysis by Spectroscopy

EBT3-based dosimeter in characterizing UVA–LEDs with lambertian radiation pattern

Calibration Transfer of Soil Total Carbon and Total Nitrogen between Two Different Types of Soils Based on Visible-Near-Infrared Reflectance Spectroscopy

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