The Narda S3-2271-101 is a non-ionizing radiation personal and area monitor for electric fields with on-site interchangeable sensor modules. Worn on the body, the Narda S3-2271-101 gives visible, audible and vibratory warnings when the electric field power density approaches or exceeds the permitted limit. The warning thresholds can be set by the user. Different sensor modules on the S3-2271-101 are available for various human safety standards.