METER AND NON-METER FALLS

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.