Weir measurement

Fundamentals:
You can calculate effluents in small drinks, rivers and artificial channels with measurement weirs by recording the overfall height.

You need to differentiate between

• Slide weirs
• Thomson weirs
• Measuring weirs

The choice for the weir depends on the given flow conditions.

Thomson weir measurements are ideal in smaller effluents without backflow (>0,05l/s and < 60 l/s), such as in the outlet of a sewage treatment plant or as temporary control measurement. Each flow Q is assigned to a clear overfall height h0 .

Target: The flow at the outlet of the sewage treatment station to the discharge system needs to be measured and the measuring signal must be available for processing.

Solution: A weir measurement with V section, according to Thomson, has a very large measuring range and measures smaller flow rates. Each flow Q is assigned to a clear overfall height, which is available in tabular form.