Question

distinguish between thermal conductivity and thermometric conductivity

Answer 1

Thermal conductivity is a thermophysical measure of how much heat is transferred through a material by the conductive flow. The thermal conductivity, or coefficient of thermal conductivity, is the quantity of heat in calories per second that passes through a 1 cm thick specimen of a cross sectional area of 1 cm2 when the temperature differential between the surfaces perpendicular to the heat flow of the specimen is 1° C. According to thermodynamics heat flows from warmer to cooler regions.

Thermal diffusivity controls the time rate of temperature change as heat passes through a material. It is a measure of the rate at which a body with a nonuniform temperature reaches a state of thermal equilibrium.

Under real life conditions, temperatures are not held constant, which means that thermal transfer through the material decreases theJim thermal gradient. Under such conditions, thermal diffusivity becomes important. The formula for thermal diffusivity (h) to thermal conductivity is

h = k/(cpp)

where k = thermal conductivity, cp = is the temperature-dependant specific heat capacity, and  p = is the temperature-dependent density.

For a given volume of material, the heat required to raise the temperature a given amount depends on its heat capacity aand the density. When the product of heat capacity and density is high, the thermal diffusivity may be low, even though the thermal conductivity is relatively high. Therefore, both thermal conductivity and thermal diffusivity are important parameters in predicting the transfer of thermal energy through a material.

To protect the pulp from a thermal shock, a liner or a base is placed under some restorations. The effectiveness of a material in preventing heat transfer is directly proportional to the thickness of the liner or the base and inversely proportional to the square root of the thermal diffusivity. Thus, the thickness of the remaining dentin and the liner or base is as important as, if not more than, the thermal properties of the materials.




thermometric conductivity also known as THERMAL DIFFUSITY

Answer 2

Answer: Thermal Conductivity is the ability of a substance to conduct heat whereas thermometric conductivity is the measurement of the rate of heat transfer from one end which is hot to another end that is cold.

Explanation:

Thermal Conductivity: the ability of a substance to conduct heat through itself.

Thermometric conductivity: It is the ratio of thermal conductivity and specific heat capacity multiplied by density.