Open Channel Flow Sensors

We offer systems and sensors to monitor and record water flow through open channels. We can help you to design a complete monitoring and control system, or simply sell you the parts and sensors that you require. We have been working in the flow monitoring business for many years and have the experience and knowledge to help you find the meters, devices and systems to meet your project needs.

Open Channel Flow

Open channel flow is generally any flow through a ditch or conduit that is not pressurized. We offer other sensors and meters for a pressurized system, or full pipes. It is very common to use flumes or weirs in open channel ditches.

We offer water level sensors, which can be configured to “calculate” flow in ditches or non-pressurized conduits. This option is often called a rated section or rated flow. This is only recommended if an estimated flow rate will be acceptable. This procedure requires flow to be manually measured using a device like the flow probe shown further down on this page.  Once flow has been measured at different depths in the channel you can build a rating table that uses depth to estimate the flow rate. We can be hired to come to your location and create a flow rating table, this often takes multiple site visits. One consideration to this option is that vegetation and silting of the channel can affect this calculation throughout the season.

Area Velocity Meters

Area Velocity flow sensors can be installed in the bottom of a ditch, channel, or conduit. They use ultrasonic pulses to measure both the depth and the velocity of the water which gives it the ability to calculate flow (discharge). These systems are very convenient due to the simple installation, but tend to be a little bit more expensive than small flumes or weirs.

flow meter open channel

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Flow Probe

We also offer the Global Water Flow Probe. This velocity measuring device is very handy for doing flow spot checks in open channel and culvert type applications.

The Flow Probe incorporates the unique Turbo-Prop propeller sensor, which uses the most accurate positive displacement technique available for velocity sensing. The Turbo-Prop is designed to shed debris and is protected inside a 2-inch diameter housing. The probe housing may be placed directly on the bottom of a pipe or streambed for measuring low flows down to 2 inches in depth. The propeller rotates freely on its bearing shaft with no mechanical interconnections for minimal friction. Magnetic material in the propeller tip passes a pickup point in the water velocity meter handle producing electrical impulses that are carried to the readout display by an internal cable. The turbo-prop is easily removed for cleaning or replacement.

The Flow Probe also has a water velocity computer, which converts the reading to feet per second (or meters per second).  The large LCD screen displays the average, minimum, and maximum water velocity readings. Up to 30 readings can be stored in the water velocity computer, and these can be reviewed for later analysis. The water velocity computer has a water-resistant housing, and a non-replaceable battery that will last approximately five years with normal use.

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