What type of heat is not measurable with a thermometer?

Latent heat refers to the amount of energy absorbed or released by a substance during a phase change without a change in temperature. In processes such as melting or boiling, heat is added or removed, but the temperature of the substance remains constant throughout the phase change. Because the temperature does not change during these transitions, latent heat cannot be measured directly with a standard thermometer, which relies on changes in temperature to provide readings.

In contrast, specific heat and sensible heat are both related to changes in temperature and can be measured directly with a thermometer. Specific heat refers to the amount of heat needed to change the temperature of a unit mass of a substance by one degree Celsius. Sensible heat involves changes in temperature that can be detected by a thermometer. Conduction heat relates to the transfer of heat through materials due to a temperature gradient and can also be associated with temperature changes. Thus, these forms of heat can be measured, while latent heat remains unmeasurable through temperature variation during phase changes.