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CO2 is one of the main gases leading to the global greenhouse effect. Based on the absorption principle of non-dispersive infrared (NDIR) spectroscopy in the field of industrial application of CO2 sensor. In the flue gas pipeline application site environment, water vapor will influent the sensor. The study on super hydrophobic transparent coating process of gold plating layer was carried out. The...
In this paper, we employed a temperature-tuned terahertz time domain spectroscopy (THz-TDS) to measure THz spectroscopic features of four amino acids, i.e., L-alanine, L-asparagine, L-cysteine and L-tyrosine in the temperature range of 4.5–300K. The THz spectra of four amino acids were found to be sensitive to temperature change. All of the amino acids have blue-shift phenomenon with about 0.10 THz...
Different oxygen gas sensing technologies, i.e., potentiometric, amperometric, paramagnetic and tunable diode laser spectroscopy (TDLS) are reviewed in details. Special attention is given to the theoretical aspects and operation basics of the technologies, application limits and analyzers or system requirements. A comprehensive technologies review is supported with the latest developments trends especially...
Tunable diode laser absorption spectroscopy (TDLAS), as a time-resolved in situ and non-intrusive technique which allows combined measurement of selected gas concentration, temperature and velocity, has shown great potential and advantages in ground tests. Recent advances make it increasingly common to use multiple lasers for simultaneous measurements, this is to say, TDLAS have the capability of...
A Non-dispersive Infrared (NDIR) sensor for carbon monoxide (CO) was used to investigate the effects of physical and chemical factors on the accuracy of the sensor. The sensor's measurement range was 0.05 – 200 ppm. It was found that the measurement error of the NDIR at 50 ppm of CO was the lowest. Moreover, the increase of concentrations of the interferential gases (CO2, NO, NO2) led to the decrease...
IC's SEE sensitivity may depend on temperature. Traditional ion irradiation methods have some limitations, which laser SEE technique can overcome. In this work, SEE laser test results for various temperatures are discussed.
Laser absorption is ideal for monitoring reactive systems with applications ranging from fundamental studies of combustion chemistry to control of power plant emissions. Sensor design, new schemes for sensitivity in harsh environments, and successful applications are reviewed.
Freeze drying is used to produce dry solid from a solution to improve product stabilization. We have applied absorption spectroscopy to monitor water sublimation rates and determine product temperature during drying, a critical process parameter.
Nitrogen dioxide is a well-known pollutant which has effect on human health, with pulmonary problems, and on the atmosphere chemistry, where it is responsible for acid rains for example. Consequently, current European standards impose very low NO2 emission thresholds in exhaust gases. Thus, there is a need for novel sensors able to monitor small NO2 concentrations for real time adjustments of engines...
A single-diode-laser sensor using first harmonic based on tunable diode laser absorption spectroscopy (TDLAS) is demonstrated to provide rapid and accurate temperature measurements, and two carbon dioxide absorption lines at 6241.402828 and 6242.672190 cm−1 with different temperature dependence are analyzed. First of all, the first harmonic peak-peak values and the average values of the two absorption...
In this paper, we introduce our isoclinic-point “atomic thermometer.” Briefly, in vapor-cell atomic clocks one of the primary impediments to long-term frequency stability derives from vapor temperature fluctuations. We believe that the isoclinic-point thermometer may be a means of more accurately assessing and stabilizing temperature in these clocks. Here, we review the spectroscopic nature of the...
Resonant near-infrared excitation induces localized heating of colloidal gold nanorod dispersions. We show that detection and imaging are possible using Terahertz (THz) waves, which possess absorption and refractive indices sensitive to water temperature change.
Infrared has been widely used in many engineering applications especially in medical devices. For example, in biomedical engineering, infrared based sensors are used to detect and measure human body composition such as water content, fat percentage and muscle mass. Infrared based sensors are popular as it enables a fast and non-destructive method to detect fat content and water in food items. Many...
This paper reviews the past efforts of solar assisted-single effect vapour absorption cooling system for buildings. Besides the review of the past theoretical and experimental investigations of solar absorption cooling systems, some new ideas were introduced to reduce heat transfer loss to generator and thus to increase COP to get effective cooling. An experimental setup of vapour absorption cooling...
We describe a new approach for molecular mixing ratio measurements based on spectral lines matching of various molecules with oxygen resulting in substantial reductions of temperature and pressure induced errors and close weighting functions matching.
The development of optical fiber temperature sensor in recent years, promoting the development of temperature measurement on line. For example, temperature monitoring in the high-voltage power system equipment to monitor the operational status of their security operation and it plays a decisive role in life too. The system uses semiconductor absorption optical fiber temperature sensor to measure temperature,...
Simulations were performed to demonstrate temperature tomography using circular 32 pixel-radius temperature and (randomised but smoothed) concentration phantoms. The simulations were run on a sensor head configuration constituting 36 sets of 32 parallel beams with equal angular spacing over 180°. For each beam, data from the HITRAN 2008 database was used to simulate direct absorption measurements...
Strong absorptions due to atmospheric oxygen near 60 GHz provide the means for remote sensing of atmospheric temperature fluctuations that may indicate the presence of disturbances such as high-altitude clear-air turbulence, aircraft wake turbulence, and severe weather. These emissions may be polarized due to the presence of aerosols or possibly some other undetermined cause. This paper describes...
The CO2 transitions near 2.6 μm are analized systematically to find the best line pairs for measurement of gas temperature and CO2 concentration in a elevated temperature environment. A line pair of CO2 at 3727.94 cm-1 and 3728.41 cm-1 is selected based on some selection criterions. The selected line pair is useful for development of CO2 concentration and temperature TDL sensors.
Tunable Diode Laser Absorption Spectroscopy (TDLAS) can offer significant opportunities and advantages for in-situ measurements of multiple parameters in gas dynamic and combustion flows. In this paper, with regard to Rocket Based Combined Cycle (RBCC), which is hydrocarbon combustion environments over the temperature range 1000-2500K, three beams diode laser sensor based on Direct Absorption Spectroscopy...
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