How is a Faraday cage employed to protect sensitive measurement equipment?

A Faraday cage is employed to protect sensitive measurement equipment by creating an electrically conductive enclosure that blocks external electromagnetic fields. Sensitive measurement equipment can be susceptible to interference from electromagnetic radiation, such as radio waves, microwaves, and electrostatic discharges. This interference can introduce noise into the measurements, leading to inaccurate results. A Faraday cage works by distributing any external electromagnetic fields around the outside of the cage, preventing them from penetrating the interior. The cage is typically constructed from a conductive material, such as copper or aluminum mesh, and is grounded to provide a path for the current to flow to earth. When an external electromagnetic field impinges on the cage, it induces currents in the conductive material. These currents create an opposing electromagnetic field that cancels out the external field inside the cage. For example, a spectrum analyzer used to measure radio frequencies can be placed inside a Faraday cage to shield it from external radio signals, allowing it to accurately measure the signals of interest. The effectiveness of a Faraday cage depends on several factors, including the conductivity of the material, the size and spacing of the mesh openings, and the grounding of the cage. Smaller mesh openings and better grounding provide greater shielding effectiveness. Therefore, Faraday cages prevent outside radiation from disturbing sensitive tools.