Flow & discharge: measure with confidence in any condition

Hydrologists typically rely on four well‑established approaches:

• Velocity–area method: divide the cross‑section into subsections, measure depth and velocity, sum all contributions.
• Rating‑curve method: relate continuous water level (stage) to discharge at a gauging station.
• Non‑contact surface‑velocity methods: use radar or imaging to estimate surface speed and infer mean velocity.
• Direct and indirect alternatives: such as dilution methods, slope‑area methods, or hydraulic structures (e.g., weirs, flumes).

• Mechanical propeller meters for wading measurements
• Electromagnetic current meters for velocity measurements in a range of conditions.
• Acoustic Doppler instruments (ADCP/ADP) for deep rivers, profiling, and mobile transects.
• Non‑contact radar for surface‑velocity monitoring when safety or debris limits in‑water deployment. 
• Stage‑based gauging stations and rating curves for continuous discharge estimation through water‑level tracking.

Ott has been innovating in hydrological instrumentation since 1873, when Albert Ott founded the company in Kempten, Germany. Early products included mechanical water level recorders and hydrometric current meters, and Ott has remained a leader in hydrology and meteorology for over 150 years.

Site design is foundational: channel shape, flow uniformity, accessibility, and safety determine measurement quality and method suitability. Straight, uniform reaches and well‑placed gauges produce more reliable data.

We offer site‑design support as a service to help you determine the ideal location, instrument class, and long‑term configuration for dependable discharge monitoring.