The Jewell Instruments Model A820 Series tiltmeter is a high precision submersible tiltmeter for use in fresh and salt water applications. Using an absolute gravity referenced electrolytic sensor, the A820 delivers superior measurement accuracy with virtually no long-term drift. High-gain units are sensitive to less than 0.0017 mm/m or better. Output is a stable ±5 VDC, which can be read with any VDC input data recorder. All units are rated to 200 meters waterproof for advanced protection from the elements. Use the A820 "Shallow Water" for structural monitoring, angle measurement and control, platform leveling and more.