Development of an optical pH measurement system based on colorimetric effect

Solar simulator is used to analysis characteristic of the solar cells. The non-uniformity is its major performance. The traditional non-uniformity measurement calls single detector method. The paper’s objective is to design and construct an array detector scanning system and to determine the optimal scanning time to achieve the lowest uncertainty. To investigate the non-uniformity by our proposed method and the traditional method, our detector consisted of eight photodiodes mounted on an arm of a linear motion lead screw to guide the detector scaning onto the lighting area. A microcontroller applied for controling and measuring light irradiance in 64 points corresponding to IEC 60904-9 standard. The results showed that the array detector scanned at a speed of 33.33 mm/s to obtain the non-uniformity with the lowest uncertainty, less than 0.6%. Analysis results of the non-uniformity obtained from our system on the test areas of (mm×mm) 156×156, 166×166 and 200×200 compared with the single detector. It showed that the mean absolute error was 1.27. Our system provided a lower uncertainty than the traditional method. The measurement accuracy was acceptable. The advantage is for testing on different test areas within a single device. The measurement time is around 1/32 of the traditional method.

Section: Array Of Photo Detectormentioning

confidence: 99%

“…The experimental procedure was described in the section 3.2. The mean absolute error (MAE) of the results between two methods had to analyze [22], [27]. The results of the non-uniformity of irradiance on different test area and the array scanning time of our prototype were shown in Table 5 and 6.…”

Section: The Analysis Of the Non-uniformity Of Irradiancementioning

confidence: 99%

Experiment analysis of non-uniformity measurement by array detector scanning system

Watjanatepin

Sritanauthaikorn

Boonmee

et al. 2022

“…The chemical, physical, and biological qualities of water are referred to as "water quality". Thus, in order to define water quality, several physical, biological, and chemical parameter elements that have a significant impact on it must be recognized [7]. These parameters feature a body of water to indicate its suitability for a certain value, such as potability, ecosystem status, agriculture, industry, or recreation [8].…”

Section: Introductionmentioning

confidence: 99%

Artificial neural network modeling for predicting the quality of water in the Sabak Bernam River

Affandi

Rahman

Ani

et al. 2022

Self Cite

Water <span>quality prediction is aided by environmental monitoring, ecological sustainability, and aquaculture. Traditional prediction approaches capture the nonlinearity and non-stationarity of water quality well. Due to their rapid progress, artificial neural networks (ANNs) have become a hotspot in water quality prediction in recent years. ANNs are utilised in this study to predict water quality using soft computing techniques. The feedforward network and the standard back-propagation method of Levenberg-Marquardt and scaled conjugate gradient learning algorithm were employed in this research. One hidden layer has been recommended for the modelling, with the number of hidden neurons set at 3, 24, and 49. For this analysis, six different testing percentages were used, and the output data can be categorised as '0' for clean water and '1' for polluted water. From the results, it can be shown that the most optimised model was from the model of trainlm with a testing percentage of 18% and with 3 number of neurons. This most optimised model obtains an accuracy of 91.7%, the best validation performance of 0.073346 with 24 epochs, and having a receiver operating characteristic (ROC) curve that is closer to the true positive rate compared to other samples.</span>

“…Monochromatic light source is preferred in some applications with the advantages of a single wavelength implementation to reduce the complexity of processing and its design requirement. It is a good alternative due to its low power consumption as well as being portable [17]- [19]. The implementation of a monochromatic optical system has been reported in many light-emitting-diode (LED) based systems developed for various applications [20]- [23].…”

Section: Introductionmentioning

confidence: 99%

Optical absorbance of RGB LEDs in pH measurement of colorimetric solution with phenol red reagent

Dali

Azam

Rahman

et al. 2022

Self Cite

The use of red, green, and blue ( RGB ) light-emitting-diode ( LED ) is a new trend in monochromatic colorimetric sensing due to cost-effective implementation. However, the application of RGB LED in pH measurement depends on the performance of the LED colour towards the colorimetric solution of interest, hence, needs to be evaluated. This work evaluated the performance of RGB LED for pH measurement system based on colorimetric approach using phenol red as a reagent. The main objective was to identify the LED colour with the best performance in terms of signal response and a bsorbance behavior. In this work, LED and photodiode were used as optical components and NI USB DAQ with LabView as the processing software. Four samples with known pH values were prepared and tested to obtain the voltage and absorbance behavior of each LED colour. Among all, the blue LED with wavelength ranged between 450 - 495 nm showed the best sensing behavior based on its linearity and error. Both voltage response and absorbance produced linear correlation with R 2=0.883 and R 2=0.9803, respectively. The significant finding from this study is useful in selecting the best RGB LED that is suitable for colorimetric pH measurement with phenol red as its colorimetric reagent.