AJP - Regulatory, Integrative and Comparative Physiology, Vol 254, Issue 2 389-R395, Copyright © 1988 by American Physiological Society
Comparison of IR thermography and thermocouple measurement of heat loss from rabbit pinna
F. S. Mohler and J. E. Heath
Department of Physiology and Biophysics, University of Illinois, Urbana 61801.
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.
