Modulation cancellation method for measurements of small temperature differences in a gas.
نویسندگان
چکیده
An innovative spectroscopic technique based on balancing and cancellation of modulated signals induced by two excitation sources is reported. For its practical implementation, we used quartz-enhanced photoacoustic spectroscopy as an absorption-sensing technique and applied the new approach to measure small temperature differences between two gas samples. The achieved sensitivity was 30 mK in 17 s. A theoretical sensitivity analysis is presented, and the applicability of this method to isotopic measurements is discussed.
منابع مشابه
Modulation cancellation method for laser spectroscopy
We report on novel methods employing a modulation cancellation technique which result in a significantly increase in the sensitivity and accuracy of trace gas detectors. This method can be applied for isotopomer abundance quantification, temperature measurements and the detection of large molecules.
متن کاملPredicting the Hydrate Formation Temperature by a New Correlation and Neural Network
Gas hydrates are a costly problem when they plug oil and gas pipelines. The best way to determine the HFT and pressure is to measure these conditions experimentally for every gas system. Since this is not practical in terms of time and money, correlations are the other alternative tools. There are a small number of correlations for specific gravity method to predict the hydrate formation. As th...
متن کاملGenetic algorithm for Echo cancelling
In this paper, echo cancellation is done using genetic algorithm (GA). The genetic algorithm is implemented by two kinds of crossovers; heuristic and microbial. A new procedure is proposed to estimate the coefficients of adaptive filters used in echo cancellation with combination of the GA with Least-Mean-Square (LMS) method. The results are compared for various values of LMS step size and diff...
متن کاملField detection of CO and CH4 by NIR 2f modulation laser spectroscopy
A novel compact fiber-coupled NIR system based on a DFB diode laser source is employed as a portable and sensitive gas sensor for trace detection of combustion pollutant molecules. We demonstrate the performance of such an NIR gas sensor by tracing the absorption lines of CO and CH4 using 2f-WMS technique at moderate temperature of T ~ 600°C in the recuperator channel of an industrial furnace...
متن کاملGround Clutter Cancellation in Incoherent Radars: Solutions for Eiscat Svalbard Radar
Incoherent scatter radars measure ionosphere parameters using modi®ed Thomson scatter from free electrons in the target (see e.g. Hagfors, 1997). The integrated cross section of the ionospheric scatterers is extremely small and the measurements can easily be disturbed by signals returned by unwanted targets. Ground clutter signals, entering via the antenna side lobes, can render measurements at...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
- Optics letters
دوره 36 4 شماره
صفحات -
تاریخ انتشار 2011