scholarly journals Temperature-Corrected Oxygen Detection Based on Multi-Mode Diode Laser Correlation Spectroscopy

2013 ◽  
Vol 2013 ◽  
pp. 1-8
Author(s):  
Xiutao Lou ◽  
Gabriel Somesfalean ◽  
Zhiguo Zhang ◽  
Shaohua Wu
Keyword(s):  
Diode Laser ◽  
Temperature Correction ◽  
Correlation Spectroscopy ◽  
Correction Coefficient ◽  
Gas Temperature ◽  
Laser Correlation Spectroscopy ◽  
Relative Standard ◽  
Oxygen Measurements ◽  
Multi Mode

Temperature-corrected oxygen measurements were performed by using multi-mode diode laser correlation spectroscopy at temperatures ranging between 300 and 473 K. The experiments simulatein situmonitoring of oxygen in coal-combustion exhaust gases at the tail of the flue. A linear relationship with a correlation coefficient of−0.999was found between the evaluated concentration and the gas temperature. Temperature effects were either auto-corrected by keeping the reference gas at the same conditions as the sample gas, or rectified by using a predetermined effective temperature-correction coefficient calibrated for a range of absorption wavelengths. Relative standard deviations of the temperature-corrected oxygen concentrations obtained by different schemes and at various temperatures were estimated, yielding a measurement precision of 0.6%.

scholarly journals Detection of elemental mercury by multimode diode laser correlation spectroscopy

2012 ◽  
Vol 20 (5) ◽  
pp. 4927 ◽  
Author(s):  
Xiutao Lou ◽  
Gabriel Somesfalean ◽  
Sune Svanberg ◽  
Zhiguo Zhang ◽  
Shaohua Wu
Keyword(s):  
Diode Laser ◽  
Elemental Mercury ◽  
Correlation Spectroscopy ◽  
Laser Correlation Spectroscopy

Gas Thermometry Using Two-Thermocouple Radiation Correction

2017 ◽  
Author(s):  
Christopher Martin ◽  
Stephen LePera ◽  
Uri Vandsburger
Keyword(s):  
Current Approach ◽  
Temperature Correction ◽  
Surface Radiation ◽  
Bead Geometry ◽  
Gas Temperature ◽  
Empirical Estimation ◽  
Additional Information ◽  
Gaseous Flows ◽  
Two Temperature

The current work is the first in a series of investigations to develop a method for high-temperature thermometry of gaseous flows using thermocouple pairs with disparate convective properties to infer the contribution of radiation. Two thermocouples of deliberately dissimilar bead geometry are placed side-by-side in a flow while the two beads are heated by surface radiation. Their dissimilar responses to radiation cause a predictable divergence between the two temperature measurements. The current approach improves upon others found in literature owing to its in-situ measurement for convection coefficients rather than dependence on empirical estimation. Each bead is deliberately overheated, and the time constant of the thermal decay back to equilibrium indicates the intensity of convection. Here, we perform this measurement in air while varying velocity, duration of overheat, and intensity of overheat. We compare the calculated temperature correction against the known air temperature. Heat transfer through the probe wires to the ceramic probe support was found to have a strong effect on the correction, although corrected values were always closer to the actual gas temperature than the original uncorrected value. In conditions of mild radiation loading, the effect was sufficiently symmetric between the two beads to allow effective correction. All measurements indicated that if additional information about the probe body temperature was collected in addition to the thermocouple measurements, the correction could be improved significantly.

Unifying Calibration Parameters for Dielectric Moisture Meter

2006 ◽  
Vol 2 (1) ◽  
pp. 73-94 ◽  
Author(s):  
Péter Mészáros ◽  
David B. Funk
Keyword(s):  
The United States ◽  
Temperature Correction ◽  
Physical Parameters ◽  
Correction Coefficient ◽  
Prototype System ◽  
United States Department ◽  
Very High Frequency ◽  
Grain Moisture ◽  
University Of Budapest ◽  
Improved Accuracy

The Unified Grain Moisture Algorithm is capable of improved accuracy and allows the combination of many grain types into a single “unified calibration”. The purposes of this research were to establish processes for determining unifying parameters from the chemical and physical properties of grains. The data used in this research were obtained as part of the United States Department of Agriculture-Grain Inspection, Packers and Stockyards Administration's Annual Moisture Calibration Study. More than 5,000 grain samples were tested with a Hewlett-Packard 4291A Material/Impedance Analyzer. Temperature tests were done with a Very High Frequency prototype system at Corvinus University of Budapest. Typical chemical and physical parameters for each of the major grain types were obtained from the literature. Data were analyzed by multivariate chemometric methods. One of the most important unifying parameters (Slope) and the temperature correction coefficient were successfully modeled. The Offset and Translation unifying parameters were not modeled successfully, but these parameters can be estimated relatively easily through limited grain tests.

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