METER AND NON-METER FALLS
- The falls may be divided into following two types:
1. Meter falls
2. Non-meter falls.
1. Meter Falls.
- The falls which can be used to measure the discharge flowing over them, are known as meter falls.
- Such falls must have broad crest so that the discharge coefficient remains constant under variable head.
- Glacis type falls are most suitable as meter falls.
- If section of the channel at the site of the fall has to be flumed.
- From economic considerations, smooth U/S transition.
- Should be provided to avoid turbulences and also to maintain accurate stage-discharge relationship.
2. Non-meter Falls.
- The falls which cannot be use to measure the discharge passing through them, are known as non-meter falls.
- Vertical drop falls cannot be used as meter falls.
- Some vacuum is developed under the nappe of falling water, which causes non-uniform flow conditions.