scholarly journals Influence of Atmosphere on Calibration of Radiation Thermometers

Sensors ◽  
2021 ◽  
Vol 21 (16) ◽  
pp. 5509
Author(s):  
Vid Mlačnik ◽  
Igor Pušnik
Keyword(s):  
High Temperature ◽  
Spectral Range ◽  
Great Influence ◽  
Black Body ◽  
Atmospheric Composition ◽  
Measured Temperature ◽  
Naturally Occurring ◽  
Thermal Imagers ◽  
Temperature Reference ◽  
Temperature Radiation

Current process of calibrating radiation thermometers, including thermal imagers, relies on measurement comparison with the temperature of a black body at a set distance. Over time, errors have been detected in calibrations of some radiation thermometers, which were correlated with moisture levels. In this study, effects of atmospheric air on thermal transmission were evaluated by the means of simulations using best available resources of the corresponding datasets. Sources of spectral transmissivity of air were listed, and transmissivity data was obtained from the HITRAN molecular absorption database. Transmissivity data of molecular species was compiled for usual atmospheric composition, including naturally occurring isotopologs. Final influence of spectral transmissivity was evaluated for spectral sensitivities of radiation thermometers in use, and total transmissivity and expected errors were presented for variable humidity and measured temperature. Results reveal that spectral range of measurements greatly influences susceptibility of instruments to atmospheric interference. In particular, great influence on measurements is evident for the high-temperature radiation pyrometer in the spectral range of 2–2.7 µm, which is in use in our laboratory as a traceable reference for high-temperature calibrations. Regarding the calibration process, a requirement arose for matching the humidity parameters during the temperature reference transfer to the lower tiers in the chain of traceability. Narrowing of the permitted range of humidity during the calibration, monitoring, and listing of atmospheric parameters in calibration certificates is necessary, for at least this thermometer and possibly for other thermometers as well.

Rapid Synthesis of Bi Substituted Ca3Co4O9 by a Polyacrylamide Gel Method and its High-Temperature Thermoelectric Power Factor

2010 ◽  
Vol 434-435 ◽  
pp. 393-396 ◽  
Author(s):  
Ying Song ◽  
Qiu Sun ◽  
Li Rong Zhao ◽  
Fu Ping Wang
Keyword(s):  
High Temperature ◽  
Thermoelectric Power ◽  
Power Factor ◽  
Solid State Reaction Method ◽  
Polyacrylamide Gel ◽  
Measured Temperature ◽  
Thermoelectric Power Factor ◽  
Gel Method ◽  
Plasma Sintering ◽  
Polyacrylamide Gel Method

A series of polycrystalline (Ca1-xBix)3Co4O9 ( x = 0.0 ~ 0.075 ) powders were synthesized rapidly by a polyacrylamide gel method. The dense ceramics were fabricated using the spark plasma sintering ( SPS ) technique. Effects of Bi substitution on high temperature thermoelectric properties of Ca3Co4O9 were evaluated. Both the electrical conductivity and Seebeck coefficient increased with increasing Bi content up to x = 0.05, thus leading to an enhanced thermoelectric power factor. The Bi substituted sample with x = 0.05 obtained in this study has the highest thermoelectric power factor in the measured temperature range. It reaches 4.810-4 Wm-1K-2 at 700 °C, which is 26 % higher than that of Ca3Co4O9 without Bi substitution, and is by up to 15 % larger as compared to the Bi substituted sample synthesized by the solid state reaction method and the SPS technique due to the high chemical homogeneous powder prepared by the polyacrylamide gel method.

FLAVOUR REVERSION IN HYDROGENATED LINSEED OIL: I. THE PRODUCTION OF AN ISOMER OF LINOLEIC ACID FROM LINOLENIC ACID

1944 ◽  
Vol 22f (6) ◽  
pp. 191-198 ◽  
Author(s):  
H. W. Lemon
Keyword(s):  
Fatty Acids ◽  
Linoleic Acid ◽  
High Temperature ◽  
Iodine Number ◽  
Spectral Method ◽  
Linolenic Acid ◽  
Linseed Oil ◽  
Naturally Occurring ◽  
Total Fatty Acids ◽  
Isomeric Acid

Linseed oil that has been hydrogenated to a plastic consistency is subject to a type of deterioration termed "flavour reversion" when heated to temperatures used in baking or frying. Investigation of the course of hydrogenation of linseed oil by the spectral method of Mitchell, Kraybill, and Zscheile (11) has indicated that linolenic acid is converted to an isomeric linoleic acid; this acid differs from naturally occurring linoleic acid in that the double bonds are in such positions that diene conjugation is not produced by high-temperature saponification. In a typical hydrogenation, the concentration of the isomeric acid increased to a maximum, at about iodine number 120, of 18% of the total fatty acids, and at iodine number 80, at which point the plasticity was similar to that of a commercial shortening, the concentration of the isomer was 13%. Evidence is presented that the isomeric linoleic acid in partially hydrogenated linseed oil is responsible for the unpleasant flavour that develops when the oil is heated.

Measurement and calculation of the emissivity of a high-temperature black body

Metrologia ◽  
2000 ◽  
Vol 37 (5) ◽  
pp. 365-368 ◽  
Author(s):  
S Galal Yousef ◽  
P Sperfeld ◽  
J Metzdorf
Keyword(s):  
High Temperature ◽  
Black Body

Iron Disilicide as High-Temperature Reference Material for Traceable Measurements of Seebeck Coefficient Between 300 K and 800 K

2016 ◽  
Vol 46 (1) ◽  
pp. 51-63 ◽  
Author(s):  
Pawel Ziolkowski ◽  
Christian Stiewe ◽  
Johannes de Boor ◽  
Ines Druschke ◽  
Knud Zabrocki ◽  
...  
Keyword(s):  
High Temperature ◽  
Reference Material ◽  
Seebeck Coefficient ◽  
Iron Disilicide ◽  
Temperature Reference

High temperature / radiation hardened capable ARM® Cortex®-M0 microcontrollers

2016 ◽  
Vol 2016 (HiTEC) ◽  
pp. 000046-000050
Author(s):  
R. Bannatyne ◽  
D. Gifford ◽  
K. Klein ◽  
C. Merritt
Keyword(s):  
High Temperature ◽  
Lower Cost ◽  
Cmos Technology ◽  
The Other ◽  
Device Performance ◽  
High Radiation ◽  
Plastic Package ◽  
Radiation Hardened ◽  
Temperature Radiation ◽  
On Chip

Abstract VORAGO Technologies has developed a pair of ARM Cortex M0 MCUs designed from the ground up to be high temperature capable. One of these devices is specifically developed for high temperature applications, the other adds capabilities that make it suitable for use in high radiation environments as well. These devices are fabricated using a modified version of commercial bulk 130nm CMOS technology utilizing our HARDSIL® technology, which provides immunity to the increased effects of latchup and EOS encountered at higher application temperatures. In addition to the processor these devices include features more typical of low temperature SoCs including on-chip memory, timers, and communications peripherals. In addition to the ceramic package and die format typically utilized at high temperature, a new lower-cost plastic package is available that has been characterized at higher temperatures. These devices have been characterized at temperatures up to 200C and results showing the latchup behavior and device performance are provided. Some of the tradeoffs involved in creating such devices are discussed, as well as some of the similarities and tradeoffs in creating a radiation hardened devices vs. a high temperature device.

Establishment of narrow spectral band model parameters database for gas high temperature radiation characteristics

2017 ◽  
Vol 46 (7) ◽  
pp. 704001
Author(s):  
蔡红华 Cai Honghua ◽  
聂万胜 Nie Wansheng ◽  
吴 睿 Wu Rui ◽  
苏凌宇 Su Lingyu ◽  
侯志勇 Hou Zhiyong
Keyword(s):  
High Temperature ◽  
Spectral Band ◽  
Model Parameters ◽  
Band Model ◽  
Radiation Characteristics ◽  
Narrow Spectral Band ◽  
Temperature Radiation
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