![teco aclara bi-directional meter up and down arrows teco aclara bi-directional meter up and down arrows](https://es-cms-prod.s3.amazonaws.com/filer/8e/20/8e20637c-5383-46b2-8cdb-37cab20932ec/01_net-metering.png)
The echoed sound is precisely measured by the instrument to calculate the fluid flow rate.īecause the ultrasonic signal must pass through the fluid to a receiving transducer, the fluid must not contain a significant concentration of bubbles or solids. This frequency shift is in direct proportion to the velocity of the liquid. Doppler-effect flow meters use the principal that sound waves will be returned to a transmitter at an altered frequency if reflectors in the liquid are in motion. The high-frequency signal is sent into the fluid.
![teco aclara bi-directional meter up and down arrows teco aclara bi-directional meter up and down arrows](https://data2.manualslib.com/first-image/i42/207/20669/2066820/aclara-sgm1400-series.jpg)
The transducer has both a transmitter and receiver. Transit-time flow meters are designed for use with clean fluids, such as water.ĭoppler-effect ultrasonic flow meters use a single transducer. With flow, sound will travel faster in the direction of flow and slower against the flow. Upstream and downstream time measurements are compared. As fluid moves through the system, the first transducer sends a signal and the second receives it. Each transducer includes both a transmitter and a receiver function. Transit-time ultrasonic flow meters require the use of two signal transducers. The two technologies use ultrasonic signals very differently to determine fluid flow and are best applied to different fluid applications. There are two different types of ultrasonic flow meters, transit-time and Doppler-effect. As fluid flows around the bluff body, eddies or vortices are created downstream the frequencies of these vortices are directly proportional to the fluid velocity. The pulses generated as a result of blade rotation are directly proportional to fluid velocity, and hence flow rate.Ī vortex-shedding flow meter senses flow disturbances around a stationary body (called a bluff body) positioned in the middle of the fluid stream. Blade speed can be sensed by a number of techniques including magnetic pick-up, mechanical gears, and photocell. As the fluid passes through the turbine blades, the impellor rotates at a speed related to the fluid’s velocity. The velocity measurement technologies described in this section include the turbine flow meter, vortex-shedding flow meter, and ultrasonic flow meters.Ī multi-blade impellor-like device is located in, and horizontal to, the fluid stream in a turbine flow meter. The benefit of the venturi flow meter over the orifice flow meter lies in the reduced pressure loss experienced by the fluid.
![teco aclara bi-directional meter up and down arrows teco aclara bi-directional meter up and down arrows](https://assets.greentechmedia.com/assets/content/cache/made/assets/content/cache/remote/https_assets.greentechmedia.com/content/images/articles/XL-CPS-Smart-Meter_600_400_80.jpg)
#Teco aclara bi directional meter up and down arrows full
The venturi flow meter takes advantage of the velocity-pressure relationship when a section of pipe gently converges to a small-diameter area (called a throat) before diverging back to the full pipe diameter. This differential pressure is measured and a flow rate calculated based on the differential pressure and fluid properties.ĭifferential Pressure – Venturi Flow Meter As the fluid flows through the orifice, the restriction creates a pressure differential upstream and downstream of the orifice proportional to the fluid flow rate. The center of the disk is formed with a specific-size and shape hole, depending on the expected fluid flow parameters (e.g., pressure and flow range). The orifice element is typically a thin, circular metal disk held between two flanges in the fluid stream. There are a variety of differential pressure devices useful for water metering two of the more common devices include orifice flow meters and venturi flow meters.ĭifferential Pressure – Orifice Flow Meter It is this shaft that traces out a circular motion – transferring this action to a register that records flow. This motion is then transferred to a shaft mounted perpendicular to the disk. As the fluid flows through the meter passing on either side of the disk, it imparts a rocking or nutating motion to the disk. The nutating-disk flow meter consists of a disk mounted on a spherically shaped head and housed in a measuring chamber. Nutating-disk flow meters are the most common meter technology used by water utilities to measure potable-water consumption for service connections up to 3-inch. Positive Displacement – Nutating-Disk Flow Meter Volumetric water measurement can be broken down into three general operating designs: The specific measurement technology chosen will depend on a number of factors including, but not limited to, current design, budget, accuracy requirements, resolution, minimum flow rate, potable versus non-potable (or at least filtered versus non-filtered water), range of flow rates, and maximum flow rate. Water is commonly measured and sold in volumetric measurements, which allows for lower-cost metering options. Water flow measurement device comparison (click for larger view)