Watchman offers an accurate measurement of noise intensity (in dB) using a high sensitivity microphone sound sensor. The sound energy levels are converted into noise intensity (dB) using 10*log(I/Io), where I is the current intensity of the sound and Io is the minimum sound intensity (of hearing at 1 kHz for a young person under the best circumstances).
In addition, Watchman calculates TWA (the eight-hour time-weighted average noise level) as per the guidelines described by Occupational Safety and Health Administrations (United Stated Dept of Labor) in standard 1910.95 App A - Noise exposure computation standard.
Access to logs and 6-day history with email alerts (to your login email) are free-of-cost. However, if you are looking for additional features such as SMS alerts, power/internet loss detection, add users and emails with daily log snapshots etc, you will require a subscription. Please click here for details.