An Optical pH Sensor with Extended Dynamic Range for Acidic pH Based on 2-(4H -Pyran-4-ylidene)malononitrile

2017 ◽  
Vol 38 (8) ◽  
pp. 952-955 ◽  
Author(s):  
Do Ik Hwang ◽  
Hyung Jin Kim
Keyword(s):  
Dynamic Range ◽  
Ph Sensor ◽  
Acidic Ph ◽  
Optical Ph Sensor ◽  
Extended Dynamic

scholarly journals NIR-emitting aza-BODIPY dyes – new building blocks for broad-range optical pH sensors

The Analyst ◽  
2015 ◽  
Vol 140 (21) ◽  
pp. 7150-7153 ◽  
Author(s):  
Martin Strobl ◽  
Tanja Rappitsch ◽  
Sergey M. Borisov ◽  
Torsten Mayr ◽  
Ingo Klimant
Keyword(s):  
Dynamic Range ◽  
Ph Sensor ◽  
Building Blocks ◽  
Ph Sensors ◽  
Ph Indicators ◽  
Optical Ph Sensors ◽  
Ph Scale ◽  
Extended Dynamic

New NIR-emitting aza-BODIPY indicators which cover the pH scale from 1.5 to 13 are presented and combination of four of these pH indicators yields a pH sensor with an extended dynamic range from pH 2 to 9.

An Optical pH Sensor Based on Diazocine

2017 ◽  
Vol 2 (26) ◽  
pp. 7956-7960 ◽  
Author(s):  
Yanan Liu ◽  
Zuwei Song ◽  
Libin Gao ◽  
Jianzhong Li
Keyword(s):  
Ph Sensor ◽  
Optical Ph Sensor

scholarly journals Photodetector resistant to background light noise with extended dynamic range of input signals

2021 ◽  
pp. 3-8
Author(s):  
V. M. Lipka ◽  
V. V. Ryukhtin ◽  
Yu. G. Dobrovolsky
Keyword(s):  
Dynamic Range ◽  
Automatic Gain Control ◽  
Modulation Frequency ◽  
Low Frequency ◽  
Gain Control ◽  
Ambient Air ◽  
Frequency Range ◽  
Background Light ◽  
Useful Signal ◽  
Extended Dynamic

Measurement of periodic optical information signals in the background light noise with a photodetector with extended dynamic range is an urgent task of modern electronics and thus has become the aim of this study. To increase the dynamic range of the photodetector, a new version of the automatic gain control (AGC) circuit has been developed, which consists of an AGC controller, an output photodetector amplifier and an AGC detector. The authors measured the dynamic range of the photodetector when receiving optical radiation with a wavelength of 1064 nm in the power range from 2.10–8 to 2.10–5 W at a modulation frequency of 20 kHz with the AGC on. Under these conditions, the dynamic range of the photodetector was found to be up to 67 dB. If the AGC was off, the dynamic range did not exceed 30 dB. Thus, the study made it possible to create a photodetector with an extended dynamic range up to 67 dB based on a new version of the AGC circuit. The design of the photodetector allowed choosing a useful signal of a particular modulation frequency in the frequency range from 3 to 45 kHz and effectively suppresses the frequencies caused by optical interference in the low frequency range from the frequency of the input signal of constant amplitude up to 3 kHz inclusive. This compensates the current up to 15 mA, which is equivalent to the power of light interference of about 15 mW. Further research should address the issues of reliability of the proposed photodetector design and optimization of its optical system. The photodetector can be used in geodesy and ambient air quality monitoring.

scholarly journals Optical spectroanalyzer with extended dynamic range for pharmacokinetic investigations of photosensitizers in biotissue

2019 ◽  
Vol 8 (1) ◽  
pp. 46-51 ◽  
Author(s):  
G. A. Meerovich ◽  
E. V. Akhlyustina ◽  
T. A. Savelieva ◽  
K. G. Linkov ◽  
V. B. Loschenov
Keyword(s):  
Dynamic Range ◽  
Spectrum Analyzer ◽  
Pharmacokinetic Studies ◽  
Fluorescent Properties ◽  
Accumulation Time ◽  
Fluorescent Method ◽  
Calibration Samples ◽  
Hardware Circuit ◽  
Improved Accuracy ◽  
Extended Dynamic

Currently, the most promising method for the study of pharmacokinetics of drugs with fluorescent properties is the spectral-fluorescent method. In this article, we propose an algorithm for expanding the dynamic range of the spectrum analyzer by automatically monitoring the maximum spectral density in the recorded fluorescence spectrum and automatically controlled changes in the accumulation time depending on this value, followed by compensation of the output signal with regard to this change, as well as hardware circuit solutions that allow this algorithm.Testing of LESA-01-"Biospeс" spectrum analyzer, upgraded using the proposed approach, was carried out on photosensitizer dispersions based on tetra-3-phenylthiophthalocyanine hydroxyaluminium of various concentrations (from 0.01 mg/l to 50 mg/l), approximately corresponding to the concentrations realized in the process of studying pharmacokinetics in calibration samples and tissues of experimental animals.The proposed solutions that implement the algorithm for recording fluorescence spectra with automatic change of accumulation time depending on the signal level, ensured a significant expansion of the dynamic range of the spectrum analyzer (up to 3.5 orders of magnitude) and improved accuracy in pharmacokinetic studies.

FBG-Embedded Oblong Diaphragms with Extended Dynamic Range

2018 ◽  
Vol 2 (2) ◽  
pp. 1-4 ◽  
Author(s):  
Arnaldo G. Leal-Junior ◽  
Anselmo Frizera ◽  
Camilo R. Diaz ◽  
Moises R. N. Ribeiro ◽  
Maria Jose Pontes
Keyword(s):  
Dynamic Range ◽  
Extended Dynamic

A versatile quinoxaline derivative serves as a colorimetric sensor for strongly acidic pH

2018 ◽  
Vol 47 (47) ◽  
pp. 17077-17085 ◽  
Author(s):  
Riya Bag ◽  
Yeasin Sikdar ◽  
Sutapa Sahu ◽  
Dilip K. Maiti ◽  
Antonio Frontera ◽  
...  
Keyword(s):  
Single Crystal ◽  
Ph Sensor ◽  
Colorimetric Sensor ◽  
Acidic Ph ◽  
Quinoxaline Derivative ◽  
Deprotonated Form ◽  
Crystal Transformation

A strongly acidic colorimetric pH sensor induced by the acidity of [Fe(H2O)6]3+, and single crystal to single crystal transformation between the protonated and deprotonated form.

scholarly journals Preparation and Characterization of a Pectin Membrane-Based Optical pH Sensor for Fish Freshness Monitoring

Biosensors ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 60 ◽  
Author(s):  
Uswatun Hasanah ◽  
Mita Setyowati ◽  
Rustam Efendi ◽  
Muslem Muslem ◽  
Nor Diyana Md Sani ◽  
...  
Keyword(s):  
Standard Deviation ◽  
Response Time ◽  
Relative Standard Deviation ◽  
Ph Sensor ◽  
Sensor Response ◽  
Relative Standard ◽  
Optical Ph Sensor

In a simple and instant procedure for detecting fish freshness, a hydrogel and hydrophilic pectin matrix membrane was used successfully as an optical pH sensor by immobilizing the chromoionophore ETH 5294 (CI), which is very selective and sensitive for the membrane. The Pe/CI optical pH sensor exhibited excellent linearity between pH 5 and pH 9, with a sensor response time of 5 min and reproducibility of 1.49% relative standard deviation (RSD). The sensor showed response stability for 15 days and a response reduction of 8.6%. The sensor’s capability was demonstrated by the detection of fish freshness for 17 days at 4 °C.

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