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11 Cards in this Set
- Front
- Back
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What are positive displacement meters
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Usually meant for residences and small customers ranges in size from 5/8 of an inch to 2 inches . Highly accurate but large friction loss, they must be tested for accuracy every 7 to 10 years
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Positive displacement meters must have an accuracy of what
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All positive displacement meters must have an accuracy of 1.5% plus or minus
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What are some positive displacement meters
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Nutating disc meter / nodding disk meter and piston meter
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What is a nutating disc meter / nodding disc meter
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It's the most common type of water meter which uses a disc that wobbles, rotates and will sweep out specific volumes of water through each cycle
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What is a piston meter
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A piston meter is a meter with known volume that moves back-and-forth to transfer the motion to a register
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What are types of velocity/current meters
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There are turbine, multi jet, propeller, Venturi and orifice velocity/current meters
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What is a turbine meter
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It's a meter that has low friction loss and is accurate for large flows but accuracy drops when the flow is low
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What is the Venturi meter
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It compares pressure differences and determines the flow . Accurate high flow it does not have any moving parts and requires no maintenance but can be expensive heavy and bulky and not accurate at low flow rates
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What is a compound meter
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A compound meter is great when demand varies from high to low can be accurate at both those flowrates and usually comes in three parts: a large turbine meter a small positive displacement meter and an automatic closing valve
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What are some type of electronic meters
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There is insertion, ultrasonic, magnetic electronic meters
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According to AWWA meters are supposed to meet what accuracy and maintenance
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Small meter should meet up +-1.5% and should be tested every 7 to 10 years. Large meters should meet +-3% and should be serviced every 1 to 3 years
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