Comparison of IR thermography and thermocouple measurement of heat loss from rabbit pinna

1988 ◽  
Vol 254 (2) ◽  
pp. R389-R395 ◽  
Author(s):  
F. S. Mohler ◽  
J. E. Heath
Keyword(s):  
Heat Loss ◽  
Infrared Thermography ◽  
Preoptic Area ◽  
Ir Thermography ◽  
Thermocouple Measurement ◽  
Temperature Changes ◽  
Ambient Temperatures ◽  
Surface Temperatures ◽  
New Zealand White Rabbits ◽  
Methods Of Measurement

The temperature of the pinnae of male New Zealand White rabbits was measured by use of infrared thermography. At ambient temperatures of 15, 20, and 25 degrees C, the average pinna temperatures were 23.0, 28.7, and 36.2 degrees C, respectively. From these temperatures, average heat loss from the total pinna surface area was calculated to be 2.8, 3.3, and 4.4 W, respectively. Preoptic temperature changes also affect the vasomotor state of the rabbit. At an ambient temperature of 20 degrees C, cooling the preoptic area of the rabbit by approximately 1 degree C resulted in an average pinna temperature of 26.5 degrees C and a heat loss of 2.4 W. Heating the preoptic area by approximately 1 degree C resulted in an average pinna temperature of 33.5 degrees C and a heat loss of 5.4 W. Finally, pinna temperatures were measured by use of a thermocouple and infrared thermography simultaneously. When the pinnae were vasodilated, the thermocouple measurements were consistently higher than the pinna surface temperatures measured thermographically. When the pinnae were vasoconstricted, the thermocouple measurements were consistently lower than the pinna surface temperatures measured thermographically. The discrepancy between the two methods of measurement is discussed.

scholarly journals Infrared Thermography: Not a Valid Method to Track Changes in Core Temperature in Exercising Athletes

2017 ◽  
Vol 7 (1) ◽  
pp. 46-50
Author(s):  
Claude T Moorman ◽  
Blake Boggess ◽  
Harry Stafford ◽  
David J Berkoff
Keyword(s):  
Data Collection ◽  
Infrared Thermography ◽  
Core Temperature ◽  
Moderate Intensity ◽  
Ir Thermography ◽  
Temperature Changes ◽  
Valid Method ◽  
Measure Surface Temperature ◽  
Collection Period ◽  
Lower Temperature

ABSTRACT Purpose: Field measurement of core temperature typically requires rectal or other invasive, expensive core temperature methods. Infrared (IR) thermography uses a handheld camera to measure surface temperature at discrete locations. We attempted to validate IR thermography against core-temperature capsules for the tracking of core-temperature changes at rest, during exercise, and recovery. Hypothesis: Infrared thermography is a noninvasive method to follow changes in core temperature during exercise. Materials and methods: Twelve athletes swallowed an ingestible core-temperature (CorTemp) capsule 1-hour prior to exercise. Athletes refrained from drinking for 2 hours prior to or during the study. Temperatures were obtained using both the CorTemp capsule and IR thermography at 10-minute intervals for 30 minutes before exercise, during 30 minutes of moderate intensity aerobic exercise, and for 30 minutes of recovery. The temperatures were then averaged for each segment of data collection. Study design: Prospective descriptive study. Results: Infrared thermography results (rest = 34.7°C C 0.49, exercise = 34.1°C ± 0.77, recovery = 34.6°C ± 0.46) were significantly lower than with the CorTemp capsules (rest = 37°C ± 0.55, exercise = 38.6°C ± 0.47, recovery = 37.7°C ± 0.47) throughout the data collection period. There were no significant correlations between the two measurement methods (rest = 0.22, exercise = 0.07, recovery = 0.59; all p > 0.05). Conclusion: Infrared thermography is not a valid method to track core-temperature changes during exercise. In addition to IR thermography readings being consistently lower, temperature changes before, during, and after exercise showed wide and inconsistent variability. Boggess BR, Stafford H, Moorman CT III, Berkoff DJ. Infrared Thermography: Not a Valid Method to Track Changes in Core Temperature in Exercising Athletes. The Duke Orthop J 2017;7(1):46-50.

Sustained heat stress elevated corneal and body surface temperatures and altered circulating leukocytes and metabolic indicators in wether lambs supplemented with ractopamine or zilpaterol

2021 ◽  
Author(s):  
Taylor L Barnes ◽  
Rachel M Burrack ◽  
Ty B Schmidt ◽  
Jessica L Petersen ◽  
Dustin T Yates
Keyword(s):  
Heat Stress ◽  
Infrared Thermography ◽  
Body Surface ◽  
Skin Surface ◽  
Blood Monocytes ◽  
Adrenergic Agonists ◽  
Temperature Changes ◽  
Surface Temperatures ◽  
Induced Changes ◽  
Skin Temperatures

Abstract Understanding how β adrenergic agonists influence the physiology of heat stress could lead to mitigation options. We sought to investigate body surface temperatures in feedlot wethers supplemented with ractopamine or zilpaterol and exposed to heat stress for 18 d. Corneal and skin temperatures were assessed via infrared thermography at 1 and 2-m distances. Rectal temperatures and circulating leukocytes, metabolites, and electrolytes were also measured. Heat stress increased (P < 0.05) rectal temperatures in unsupplemented and zilpaterol-supplemented lambs but not in ractopamine-supplemented lambs. Heat stress also increased (P < 0.05) surface temperatures of the cornea, nose, ear, and back, regardless of supplement. Observations were comparable between thermography performed at 1 and 2 m, and higher emissivity settings generally produced less variation. Heat stress tended to increase (P = 0.08) blood monocytes in unsupplemented but not ractopamine or zilpaterol-supplemented lambs. Granulocytes were increased (P < 0.05) by heat stress in ractopamine-supplemented lambs but decreased (P < 0.05) in zilpaterol-supplemented lambs. Blood glucose, triglycerides, and cholesterol did not differ among groups, and blood lactate was reduced (P < 0.05) by heat stress in zilpaterol-supplemented lambs only. Blood Na + was reduced (P < 0.05) and Ca 2+ increased (P < 0.05) by heat stress, regardless of supplement. These findings indicate that β1 and β2 adrenergic agonists differentially relieve some but not all heat stress-induced changes in stress indicators. Moreover, corneal and skin surface temperatures measured by infrared thermography reasonably identified body temperature changes at a distance of 2 m.

Application of pyrometer and standard sample to determine surface temperature of studied materials

2019 ◽  
pp. 9-13
Author(s):  
V.Ya. Mendeleyev ◽  
V.A. Petrov ◽  
A.V. Yashin ◽  
A.I. Vangonen ◽  
O.K. Taganov
Keyword(s):  
Composite Material ◽  
Surface Temperature ◽  
Relative Error ◽  
Wavelength Range ◽  
Standard Sample ◽  
A Priori ◽  
Temperature Changes ◽  
Surface Temperatures ◽  
Relative Errors ◽  
Normal Emissivity

Determining the surface temperature of materials with unknown emissivity is studied. A method for determining the surface temperature using a standard sample of average spectral normal emissivity in the wavelength range of 1,65–1,80 μm and an industrially produced Metis M322 pyrometer operating in the same wavelength range. The surface temperature of studied samples of the composite material and platinum was determined experimentally from the temperature of a standard sample located on the studied surfaces. The relative error in determining the surface temperature of the studied materials, introduced by the proposed method, was calculated taking into account the temperatures of the platinum and the composite material, determined from the temperature of the standard sample located on the studied surfaces, and from the temperature of the studied surfaces in the absence of the standard sample. The relative errors thus obtained did not exceed 1,7 % for the composite material and 0,5% for the platinum at surface temperatures of about 973 K. It was also found that: the inaccuracy of a priori data on the emissivity of the standard sample in the range (–0,01; 0,01) relative to the average emissivity increases the relative error in determining the temperature of the composite material by 0,68 %, and the installation of a standard sample on the studied materials leads to temperature changes on the periphery of the surface not exceeding 0,47 % for composite material and 0,05 % for platinum.

Measuring Facial Skin Temperature Changes Caused by Mental Work-Load with Infrared Thermography

2016 ◽  
Vol 136 (11) ◽  
pp. 1581-1585 ◽  
Author(s):  
Tota Mizuno ◽  
Takeru Sakai ◽  
Shunsuke Kawazura ◽  
Hirotoshi Asano ◽  
Kota Akehi ◽  
...  
Keyword(s):  
Skin Temperature ◽  
Infrared Thermography ◽  
Work Load ◽  
Facial Skin ◽  
Mental Work ◽  
Temperature Changes ◽  
Mental Work Load

Changes in serotonin contents in brain affect metabolic heat production of rabbits in cold

1978 ◽  
Vol 235 (1) ◽  
pp. R41-R47
Author(s):  
M. T. Lin ◽  
I. H. Pang ◽  
S. I. Chern ◽  
W. Y. Chia
Keyword(s):  
Blood Flow ◽  
Amino Acid ◽  
Heat Loss ◽  
Acid Decarboxylase ◽  
Evaporative Heat Loss ◽  
Decarboxylase Inhibitor ◽  
Ambient Temperatures ◽  
Amino Acid Decarboxylase ◽  
Metabolic Heat ◽  
Normal Limits

Elevating serotonin (5-HT) contents in brain with 5-hydroxytryptophan (5-HTP) reduced rectal temperature (Tre) in rabbits after peripheral decarboxylase inhibition with the aromatic-L-amino-acid decarboxylase inhibitor R04-4602 at two ambient temperatures (Ta), 2 and 22 degrees C. The hypothermia was brought about by both an increase in respiratory evaporative heat loss (Eres) and a decrease in metabolic rate (MR) in the cold. At a Ta of 22 degrees C, the hypothermia was achieved solely due to an increase in heat loss. Depleting brain contents of 5-HT with intraventricular, 5,7-dihydroxytryptamine (5,7-DHT) produced an increased Eres and ear blood flow even at Ta of 2 degrees C. Also, MR increased at all but the Ta of 32 degrees C. However, depleting the central and peripheral contents of 5-HT with p-chlorophenylalanine (pCPA) produced lower MR accompanied by lower Eres in the cold compared to the untreated control. Both groups of pCPA-treated and 5,7-DHT-treated animals maintained their Tre within normal limits. The data suggest that changes in 5-HT content in brain affects the MR of rabbits in the cold. Elevating brain content of 5-HT tends to depress the MR response to cold, while depleting brain content of 5-HT tends to enhance the MR response to cold.

Ambient temperature effects on physiological traits of white-tailed deer

1975 ◽  
Vol 53 (6) ◽  
pp. 679-685 ◽  
Author(s):  
J. B. Holter ◽  
W. E. Urban Jr. ◽  
H. H. Hayes ◽  
H. Silver ◽  
H. R. Skutt
Keyword(s):  
Heart Rate ◽  
Body Temperature ◽  
Energy Expenditure ◽  
Ambient Temperature ◽  
Temperature Effects ◽  
Temperature Changes ◽  
Wind Chill ◽  
Ambient Temperatures ◽  
Energy Equilibrium ◽  
Body Energy

Six adult white-tailed deer (Odocoileus virginianus borealis) were exposed to 165 periods of 12 consecutive hours of controlled constant ambient temperature in an indirect respiration calorimeter. Temperatures among periods varied from 38 to 0 (summer) or to −20C (fall, winter, spring). Traits measured were energy expenditure (metabolic rate), proportion of time spent standing, heart rate, and body temperature, the latter two using telemetry. The deer used body posture extensively as a means of maintaining body energy equilibrium. Energy expenditure was increased at low ambient temperature to combat cold and to maintain relatively constant body temperature. Changes in heart rate paralleled changes in energy expenditure. In a limited number of comparisons, slight wind chill was combatted through behavioral means with no effect on energy expenditure. The reaction of deer to varying ambient temperatures was not the same in all seasons of the year.

Respiratory water and heat loss of the black duck during flight at different ambient temperatures

1971 ◽  
Vol 49 (5) ◽  
pp. 767-774 ◽  
Author(s):  
M. Berger ◽  
J. S. Hart ◽  
O. Z. Roy
Keyword(s):  
Heat Loss ◽  
Water Loss ◽  
Pulmonary Ventilation ◽  
Evaporative Heat Loss ◽  
Total Heat Loss ◽  
Ambient Temperatures ◽  
Black Duck ◽  
Respiratory Heat Loss ◽  
Metabolic Water ◽  
Expired Air

Pulmonary ventilation and temperature of expired air and of the respiratory passages has been measured by telemetry during flight in the black duck (Anas rubripes) and the respiratory water and heat loss has been calculated.During flight, temperature of expired air was higher than at rest and decreased with decreasing ambient temperatures. Accordingly, respiratory water loss as well as evaporative heat loss decreased at low ambient temperatures, whereas heat loss by warming of the inspired air increased. The data indicated respiratory water loss exceeded metabolic water production except at very low ambient temperatures. In the range between −16 °C to +19 °C, the total respiratory heat loss was fairly constant and amounted to 19% of the heat production. Evidence for the independence of total heat loss and production from changes in ambient temperature during flight is discussed.

Using Thermoelectric Cooling With Tourniquets for Nerve Preservation

2016 ◽  
Author(s):  
M. Trupiano ◽  
S. Aarabi ◽  
A. F. Emery
Keyword(s):  
Thermal Conditions ◽  
Ambient Conditions ◽  
Transfer Coefficients ◽  
Thermoelectric Coolers ◽  
Ambient Temperatures ◽  
Nerve Preservation ◽  
Heat Transfer Coefficients ◽  
Surface Temperatures ◽  
Element Simulation ◽  
Free And Forced Convection

The use of a tourniquet leads to nerve damage, even if applied for short periods of time. This damage can be minimized if the limb is cooled. Because of the low conductivities of human tissue, core limb cooling is slow unless the surface temperature is very cool. Subzero surface temperatures can lead to skin injury (i.e., frostbite). Ideally one would adjust the limb surface temperatures as a function of time to maximize the cooling rate while avoiding permanent tissue damage. One possible approach is to use a thermoelectric cooler (TEC) in conjunction with a programmable power supply. TEC performance varies strongly with heat absorption rate, a function of limb thermal properties, and hot side temperatures that are strongly affected by the surface conditions on the hot side, i.e., overall heat transfer coefficients and ambient conditions. The paper describes the use of finite element simulation to predict the usefulness of using thermoelectric coolers applied to the surface of a limb when compared to the standard approach of using ice packs. Since the TEC performance is strongly influenced by its warm side thermal conditions, experimental results are presented for different ambient temperatures, free and forced convection, and evaporation of water from a wickable covering.

scholarly journals Infrared Thermography applied to power electron devices investigation

2015 ◽  
Vol 28 (2) ◽  
pp. 205-212 ◽  
Author(s):  
Giovanni Breglio ◽  
Andrea Irace ◽  
Luca Maresca ◽  
Michele Riccio ◽  
Gianpaolo Romano ◽  
...  
Keyword(s):  
Failure Analysis ◽  
Infrared Thermography ◽  
Semiconductor Devices ◽  
Electronic Devices ◽  
Experimental Characterization ◽  
Ir Thermography ◽  
Power Semiconductor ◽  
Power Semiconductor Devices ◽  
Electron Devices ◽  
Lock In

The aim of this paper is to give a presentation of the principal applications of Infrared Thermography for analysis and testing of electrondevices. Even though experimental characterization could be carried out on almost any electronic devices and circuits, here IR Thermography for investigation of power semiconductor devices is presented. Different examples of functional and failure analysis in both transient and lock-in modes will be reported.

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