ANS:D - Zirconia probe is used for the humidity measurement.

The wrong statement is: "Elutriation process refers to when the soluble material is largely concentrated on the surface of an insoluble solid and is simply washed off by the solvent." Elutriation refers to a process in which particles are separated based on their size and density by subjecting a mixture of particles to a rising stream of liquid or gas. It is often used in sedimentation processes to separate particles of different sizes. The correct definition of elutriation does not involve the concentration of soluble material on the surface of an insoluble solid or its washing off by a solvent. Therefore, this statement is incorrect.