A published method determines the thermal conductivity, k, of material
without probe calibration using the maximum local slope value of a te
mperature response curve monitored by a line heat source probe. We exa
mined the applicability and validity of this method. A mathematical he
at conduction model was used for theoretical examination and a thermis
tor based probe for experimental examination with a computer based dat
a acquisition and reduction system. Glycerol (99.5% pure) and agar gel
(0.5%) were test materials. The k values estimated by the maximum slo
pe method were comparably accurate and less statistically variable com
pared to those determined by two widely used data reduction methods, t
he time correction and maximum r-square methods.