Micro-analyzer with optical detection and wireless communications

Camarillo-Escobedo, R.M.; Valdés-Perezgasga, Francisco; Rodríguez-Rivera, R.

doi:10.1016/j.sna.2013.05.019

Cited by 14 publications

(2 citation statements)

References 28 publications

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“…We have achieved the residual measurement of I m related to the diffuse radiation in the experiment. Dark measurement I k is obtained with the light source switched off and the current signal generated using a sample or a standard solution [ 40 , 43 ]. By using the residual measurement as a correction factor, we can obtain the following equation:

where A is the absorbance of the sample solution, I 0 is the initial light intensity before passing through solution, I t is the intensity of transmitted light, I k is the dark signal of photodiode, which was also generated while the residual measurement was achieved, I m is the residual measurement we achieved, k is the attenuation coefficient, l is the optical path length crossing over the sample solution and c is the concentration of the absorbing substance.…”

Section: Resultsmentioning

confidence: 99%

“…In this work, a laser light source with the wavelength of 880 nm was used according to the absorption spectrum of chromogenic reaction. The laser light source works at a power of 5 mW, which can greatly reduce the noise interference caused by power fluctuations [ 23 , 43 ]. The photographs of the light source and the photodetector are shown in Figure 2 a,b.…”

Section: Methodsmentioning

confidence: 99%

See 1 more Smart Citation

A Miniaturized Colorimeter with a Novel Design and High Precision for Photometric Detection

Yan

Chen

Pang

et al. 2018

Sensors

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Water quality detection plays an increasingly important role in environmental protection. In this work, a novel colorimeter based on the Beer-Lambert law was designed for chemical element detection in water with high precision and miniaturized structure. As an example, the colorimeter can detect phosphorus, which was accomplished in this article to evaluate the performance. Simultaneously, a modified algorithm was applied to extend the linear measurable range. The colorimeter encompassed a near infrared laser source, a microflow cell based on microfluidic technology and a light-sensitive detector, then Micro-Electro-Mechanical System (MEMS) processing technology was used to form a stable integrated structure. Experiments were performed based on the ammonium molybdate spectrophotometric method, including the preparation of phosphorus standard solution, reducing agent, chromogenic agent and color reaction. The device can obtain a wide linear response range (0.05 mg/L up to 7.60 mg/L), a wide reliable measuring range up to 10.16 mg/L after using a novel algorithm, and a low limit of detection (0.02 mg/L). The size of flow cell in this design is 18 mm × 2.0 mm × 800 μm, obtaining a low reagent consumption of 0.004 mg ascorbic acid and 0.011 mg ammonium molybdate per determination. Achieving these advantages of miniaturized volume, high precision and low cost, the design can also be used in automated in situ detection.

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