The Rugged TROLL 100 is In-Situ’s most economical option for measuring and logging water level, water pressure, and temperature. This non-vented (absolute) water level logger is ideal for flood-prone or high humidity environments, allowing you to periodically download data with the Rugged TROLL Docking Station. Plus, titanium construction gives you long-lasting performance in fresh or saline groundwater and surface-water environments.