Non-Contact Ultrasonic, Continuous Level and Open Channel Flow Measurement

Accurate Open Channel Flow Measurement of Water and Waste Water

Monitoring of flow helps planners and engineers to properly assess requirements and design systems of the right capacity or production. In open channel flow measurement, weirs and flumes are used to produce known and repeatable characteristics in the process stream. Weirs, flumes and other devices develop a liquid head that is used to measure flow rate. By measuring the time from transmission of an ultrasonic pulse to receipt of an echo, the water level or "Head" is accurately measured.

These devices are particularly useful when large flows are to be measured or where liquids are handled in open channels or in pipelines that are not ordinarily full. Open channel flow is also useful for accumulative measurement of large amounts of waste water and sewage stream. In food and beverage plants, where clean water is an important factor of the production, there is a need to measure the post-production waste water to evaluate their cost. Municipalities and waste water treatment plants also require an accurate measurement of the water flow in order to settle their accounts.

The simplest and most economical flow-measuring devices available are weirs. Basically, weirs are obstructions or dams placed across the channel containing openings or apertures of known

geometry through which flows the liquid to be monitored. Weirs may be rectangular, trapezoidal

(Cippoletti), "V" notch or a combination of these types. Head is measured as the rise in level of liquid in the pool upstream of the weir. Ultrasonic level instruments are commonly used to measure the rise in head. The use of a stilling well should be considered if foaming or excessive turbulence is encountered.

Slightly more complex devices are flumes that use complex geometries to form the process stream into a controlled flow that allows accurate and repeatable measurement over the range of the flume. The loss of head through a flume is about one-quarter that of a weir of equal capacity.

MonoScan O

The smallest ultrasonic solution for open channel flow measurement

Solid AT's MonoScan O is the smallest open channel flow gauging device in the industry. The MonoScan O is designed to work in wet environments and is therefore made of a water proofed enclosure. Its UV protected mono-block body includes both electronics and transducer designed for various types of environments.

The MonoScan O has 9 different types of flumes/weirs predefined in its memory. It measures the water level in the selected tunnel and then translates the readings to flow and displays them on its LCD screen in GPM or M³/Hr. Its loop-powered 4-20mA configuration can provide measurement readings to a remote PLC or locally on its LCD.

SmartScan 50 O

Simplifes Water Flow Calculations

The SmartScan 50 O is based on an electronic unit and highly sensitive transducer with 0.2% accuracy.

It supplies 9 different types of flumes and weirs preprogrammed in its memory, and a customization option that allows insertion of up to 24 leaner points of customized flume dimensions. The SmartScan 50 O measures the level of water in the channel and converts it into flow which is then displayed on its LCD screen in GPM or M³/Hr units. Every cubic meter of water recovered as a result of improving water measurement produces more revenue than the same amount obtained from a new source.

To simplify the process of waste water flow calculation between municipalities and waste water treatment plants the SmartScan 50 O provides a totalization function. This function is an accurate

measurement tool that presents calculation of accumulated readings of clean water and waste water flow over time.

Its compact transducer of glass-reinforced epoxy allows installations in corrosive and gassy surroundings. The flow readings can be transferred digitally via RS 485 communication and analogically through 4-20mA.