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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... 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 . Techniques for ...
... 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 . Techniques for ...
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... determine the radiation error in temperature measurements made with thermocouples , thermistors , and a resistance ... determination of the thermodynamic proper- ties of moving air , these errors can be significant at air velocities ...
... determine the radiation error in temperature measurements made with thermocouples , thermistors , and a resistance ... determination of the thermodynamic proper- ties of moving air , these errors can be significant at air velocities ...
Page 2
... determining if there were any conduction errors involved during testing ( 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 ...
... determining if there were any conduction errors involved during testing ( 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 ...
Page 3
... is approximately constant . It appears in the equation R = Roe where T is any Kelvin temperature , and T. is the temperature at which R. was determined . DUCT WALL METALLIC AIR MIXERS DIRECTION OF AIR FLOW THERMO- 3 Calibration___.
... is approximately constant . It appears in the equation R = Roe where T is any Kelvin temperature , and T. is the temperature at which R. was determined . DUCT WALL METALLIC AIR MIXERS DIRECTION OF AIR FLOW THERMO- 3 Calibration___.
Page 5
... determined by special tests and the errors were found to be very small but measurable . Details on how measurements and cor- rections for the small errors were made are given later . 14 FIGURE 5. Large shield and the reference sensor ...
... determined by special tests and the errors were found to be very small but measurable . Details on how measurements and cor- rections for the small errors were made are given later . 14 FIGURE 5. Large shield and the reference sensor ...
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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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