The axisymmetric transient heat conduction problem of a thermocouple embedded in a low thermal conductivity material is analytically investigated. The thermocouple is positioned normal to a surface which is heated by a time-variable heat flux. The results of the analysis are presented as dimensionless curves for a variation of several dimensionless parameters. The analysis may be used to calculate: (a) The temperature of a thermocouple temperature measurement for a known heat flux. (b) The undisturbed temperature at the location of the thermocouple junction from the transient thermocouple measurement. (c) The undisturbed heat flux just before thermocouple from the thermocouple measurement. It is found that the temperature disturbances in the thermocouple reading due to the presence of the thermocouple itself may be very large. It is shown that in certain cases the disturbance could be as large as 50 per cent of the temperature rise. An example is given in which the disturbance reaches 700 deg F.