Radiation Errors in Air Ducts Under Nonisothermal Conditions Using Thermocouples, Thermistors, and a Resistance ThermometerU.S. National Bureau of Standards, 1969 - 12 pages Studies were made to determine the radiation error in temperature measurements made with thermocouples, thermistors, and a resistance thermometer in moving air at velocities ranging from 300 to 1300 fpm when the temperature of the duct wall surrounding the air stream was from 0 to 50 deg F higher than that of the air in the center of the duct. To eliminate all but the variable under study, conduction errors were minimized to a point where they were almost nonexistent by using Chromel P-constantan thermocouple wire and by employing other techniques. Radiation effects were studied when the probe housing the three types of temperature sensors was unshielded and again when it was shielded. Under the test conditions that prevail in the testing of air conditioners and heat pumps in laboratories, it should be possible to reduce the error in temperature measurement of the moving air to about 0.2 deg F by a suitable combination of air mixers, duct insulation, radiation shields, and calibration techniques. (Author). |
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... Experimental Determination of Eccentricity of Floor Loads Applied to a Bearing Wall . 15 cents BSS15 . Interrelations Between Cement and Concrete Properties : Part 4 , Shrinkage of Hardened Portland Cement Pastes . 75 cents BSS16 ...
... Experimental Determination of Eccentricity of Floor Loads Applied to a Bearing Wall . 15 cents BSS15 . Interrelations Between Cement and Concrete Properties : Part 4 , Shrinkage of Hardened Portland Cement Pastes . 75 cents BSS16 ...
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... ( experiments performed to make this determina- tion are described later ) ; and a wooden cabinet ( D ) , which housed an ice bath and a junction box . The junction box , which had gold - plated connectors to minimize corrosion , was used ...
... ( experiments performed to make this determina- tion are described later ) ; and a wooden cabinet ( D ) , which housed an ice bath and a junction box . The junction box , which had gold - plated connectors to minimize corrosion , was used ...
Page 4
... was used for the reference value . Details of the experimental program required that two different types of reference sensors be used . The first , used for the tests where the probes were shielded , fitted snugly into the inner of two 4.
... was used for the reference value . Details of the experimental program required that two different types of reference sensors be used . The first , used for the tests where the probes were shielded , fitted snugly into the inner of two 4.
Page 8
... experimental verification was made . Hot metal , about 50 deg F hotter than the temperature of the duct wall , was applied suddenly in the hollow phenolic tube ( designated as C on figure 1 ) to the plastic tube housing the lead wires ...
... experimental verification was made . Hot metal , about 50 deg F hotter than the temperature of the duct wall , was applied suddenly in the hollow phenolic tube ( designated as C on figure 1 ) to the plastic tube housing the lead wires ...
Page 11
... experimental work resulted in small errors in the observed re- sults . For the tests where the probe was shielded , the possible error in experimental results was rela- tively large when compared to the radiation error reported . This ...
... experimental work resulted in small errors in the observed re- sults . For the tests where the probe was shielded , the possible error in experimental results was rela- tively large when compared to the radiation error reported . This ...
Common terms and phrases
15 cents 50 deg F access door Achenbach air mixing air velocity aspirated assembly automatic data processing Building Science Series Bureau of Standards calibration Cement and Concrete Chromel P-constantan thermocouple Concrete Properties Conditions Using Thermocouples curves deg F 28 determined Dewar flask diameter DIFFERENCE IN TEMPERATURE duct wall error in temperature experimental Faison FPM UNSHIELDED heat pumps heated section ice bath immediately upstream inlet air inner shield Institute for Applied instrument room insulated Interrelations Between Cement junction box large reference sensor mercury-in-glass thermometers minimizing conduction errors moving air National Bureau Nonisothermal Conditions OBSERVED READINGS platinum resistance thermometer Portland Cement radiation error radiation shields Reinhold Publ SENSORS dag F set of shields shielded probe shielded sensors shown in figure small reference sensor techniques temperature difference temperature measurement temperature sensors test conditions test duct test probe thermal conductivity thermistors thermo thermocouple wire types of sensors U.S. Government Printing velocity of 300
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