Flow Measurement
Solution for Excessive Approach Velocity In Flumes
Accurate flow rate measurement is highly dependent upon the approaching flow conditions. The approaching flow should be well distributed, laminar, and free of surface waves. To aid in the transition of flow from what is typically a wider approach channel into the flume, the use of curved wingwalls or flared transitions should be used to…
Read MoreThe New Isco LaserFlow Non-Contact Flow Meter
We are excited to announce that in October 2012, Teledyne Isco will begin shipping the new LaserFlow non-contact flow meter. The LaserFlow meter remotely measures flow in open channels with non-contact Laser Doppler Velocity technology and non-contact Ultrasonic Level technology. The LaserFlow is unlike other non-contact flow meters which only measure surface velocity. The LaserFlow…
Read MoreMeasuring River Discharge – The Great Mississippi River Flood of 2011
Measuring River Discharge is a common project as the Gulf South representative of Teledyne RD Instruments. We are often called in to support important measurements. During the record flood event in spring 2011, we demonstrated the capability of the RDI RiverRay ADCP for the USACE ERDC. Their local support consultant Dimco, needed a capable Acoustic…
Read MoreSelecting a Flume For an Existing Pipe or Channel
Open channel flow measurement can be a challenge in applications that require the placement of a flume in an existing pipe or channel. While most everyone is familiar with Parshall Flumes, in many cases, there are other flume options that can provide for equal or better accuracy and are better suited for a particular pipe…
Read MoreReal Time Water Quality Monitoring on Rivers
Long term water quality monitoring on rivers can be an arduous chore; and very expensive. The cost of sending teammates into the field continues to skyrocket, especially when it is over water; not to mention the inherent safety concerns. All this for what amounts to a ‘snap-shot’ of water quality at the time of measurement…
Read MoreFlow Measurement at an Industrial Outfall Using the Index-Velocity Rating Method
Channels with a large depth to width aspect ratio present a challenge when it comes to accurately measuring flow rates in real time. The index velocity method provides a solution for real time flow rate reporting in situations where traditional stage-discharge ratings are not possible. The index velocity method uses a mathematical model to calculate…
Read MoreParshall Flumes – Free vs. Submerged Flow
As often as we use Parshall flumes for open channel flow measurement, it is important to understand “free versus submerged flow” conditions; as it greatly impacts the accuracy of the installation…or the lack thereof. While any primary device could be affected by submerged flow conditions, there isn’t much data to be found on the topic.…
Read MoreThe Thelmar Weir – Insertable Volumetric Weir for Flow Measurement in Pipes
Thelmar Insertable Volumetric Weirs are commonly used for temporary flow measurement in a pipe, or manhole; with relatively low flows. The Thelmar weir is calibrated compound weir that is inserted into the invert of a pipe and incorporates a 90° v-notch for measuring lower end of the range; then opens into a rectangular weir at…
Read MoreAquatic Sensor Workgroup Guidance Documents
The Aquatic Sensor Workgroup is a public-private partnership of water-quality monitoring agencies, industry, and academia whose mission is to ensure that water-quality data collected by sensors are of known and documented quality. They have published several guidance documents that benefit anyone using or preparing to use water quality monitoring sensors for surface water or groundwater monitoring applications.
Read MoreFlow Validation of London Avenue Pumping Station for the USACE New Orleans Levee System
On July 26, 2007 C.C. Lynch & Associates Inc., participated in a flow validation study in conjunction with the USACE Engineering Research Development Center (ERDC) for the purposes of determining the pumping capacity of the New Orleans Levee London Avenue Pumping Station pictured below.
Read MoreCriteria for Proper Weir Design
The sharp-crested weir is probably the most common open channel primary device we find for measuring flow. It is basic, and usually, the least expensive design option. While most weir installations we encounter do perform well, they are too often outdated, misapplied, or not maintained for present flow conditions. Many of our customers are surprised…
Read MoreFlow Measurement Solution….The H-Flume
Recently, an industrial plant needed an accurate means to measure flow from a tank. Since most commonly used flow equations for weirs rely on a sharp-crested weir plate, the thick tank sidewall presented an issue. We were uneasy with assumptions, no flow chart, and exactly how to convert level to flow rate. Too, windy conditions…
Read MoreFlume Selection Guidance
One of the most frequent requests that we get from civil engineers during WWTP design is for flume selection guidance. While there are many complex aspects that need to be considered in flume selection and outfall channel configuration, there are a few basic considerations that can be evaluated to streamline the process.
Read MoreVarious Techniques For Flow Measurement At Wastewater Lagoons
There is a stir in flow measurement into and out of sewer lagoons. More and more, we are asked about influent flow measurement for sewer lagoon(s); as engineers try to get a idea on influent flow characteristics; such as peak, dry vs. wet (I&I) and influent load. Many influent lines can be a challenge; as…
Read MoreFinally Say Goodbye to Circular Chart Recorders!
ISCO’s Signature meter is for open channel flow monitoring at wastewater treatment plants, industrial pretreatment and permanent outfall monitoring locations. The Signature has bubbler and/or ultrasonic level sensor options – plus an array of additional sensor inputs; such as pH, DO, Turbidity, Chlorine, etc.
Read More