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

• Published in: The American journal of physiology Vol. 254; no. 2 Pt 2; pp. R389 - R395
• Main Authors: Mohler, F S, Heath, J E
• Format: Journal Article
• Language: English
• Published: United States 01-02-1988
• Subjects: Algorithms; Animals; Body Temperature Regulation; Ear, External - blood supply; Male; Rabbits; Spectrophotometry, Infrared; Thermography - methods
• ISSN: 0002-9513
• DOI: 10.1152/ajpregu.1988.254.2.R389

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.