What do thermal elements infer level by measuring?

Thermal elements infer level by measuring temperature because they rely on the principle that changes in temperature are associated with changes in the physical properties of the fluid being measured. These elements typically operate based on the behavior of a liquid or gas when subjected to heat. As the level of the fluid changes, the temperature of the thermal element changes accordingly, allowing for the determination of fluid level through the measured temperature differences. This relationship between temperature and level is fundamental to the operation of thermal level measurement devices, making temperature the correct basis for inference in this context.

While capacitance, thermal conductivity, and displacement are methods used for other types of measurements, they do not specifically relate to how thermal elements determine level. Capacitance relies on changes in electric capacitance due to fluid properties, thermal conductivity measures the ability of a material to conduct heat, and displacement is a term often used in mechanical measurements rather than thermal methods. Therefore, these options do not align with the function of thermal elements in inferring level through temperature measurement.