Flumes For Water System Open Channel Flow Measurement

This cutthroat flume is one of several types of flumes
used to facilitate open channel flow measurement.
Image courtesy Tracom Fiberglass Products

The measurement of flowing water in an open channel can be facilitated by applying known methodologies and a specifically shaped restriction in the flow path. The restriction is called a flume.

A flume, as applied to open channel flow, is a fixed structure in the flow path that directs or restricts the flowing water in a manner that allows a measurement of the fluid depth at a defined point to be translated into a volumetric flow rate. There are several different types of flumes, each with a characteristic measuring procedure used to determine flow volume. Applications for flumes and their open channel flow measurement techniques are commonly found in agriculture, sewer systems, water treatment, and industrial effluent measurement stations.

Flumes can provide measurement accuracy suitable for many uses. Advantages are their simplicity, ease of maintenance, comparatively small footprint, and ability to measure large flows. Fiberglass flumes provide solid long term performance due to their corrosion resistance and smooth, easy to maintain, surface. Prefabricated units can be shipped to an installation site and easy installed.

Share your open channel flow measurement challenges with application specialists, leveraging your own knowledge and experience with their product application expertise.

Groundwater Monitoring Instrumentation

The Level TROLL groundwater monitoring instrument can be
suspended in a well and log temperature, pressure, and level.
Image courtesy In-Situ

In-Situ specializes in the manufacture of instruments used for monitoring groundwater and other water testing functions. In the fields of aquaculture, remediation, energy, mining and research, In-Situ is regarded as an innovator, providing reliable top quality water monitoring equipment.

The company's Level TROLL line of water level data loggers are specifically intended for aquifer characterization. The instruments provide continuous level, pressure and temperature readings when suspended in a well. The battery operated units can function for very long periods, holding up to 260,000 data points.

The Level TROLL Instrument is completely sealed and contains no user-serviceable parts. The instrument includes pressure and temperature sensors, a real-time clock, microprocessor, sealed lithium battery, data logger, and memory. Instruments are available in a variety of pressure (depth) ranges with vented and non-vented sensors. Placement within a well can be accomplished with In-Situ's Rugged Cable System, custom built for each application to provide direct reading operation. The cable assembly includes titanium twist-lock connectors, desiccant to prevent condensation in the vent tube, shielded connecting cable, and a placement grip for secure deployment. A second option for instrument deployment is suspension via a polyurethane coated stainless steel cable for applications that do not require direct reading, only data logging.

There are several models from which to choose, and other products suitable for groundwater monitoring throughout many industries. Share your water monitoring requirements of all types with instrumentation specialists. Combine your own knowledge and experience with their product application expertise to develop effective solutions.

Well Water Level Monitor from Instrument Specialties, Inc.

Open Path Laser Spectroscopy Gas Detection

MSA has been a leader in hazardous gas detection instruments and equipment for many years. Their addition of the Senscient ELDS™ open path gas detector to their already extensive array of gas detection instruments reinforces the MSA leadership position in the field.

The Senscient ELDS™ system consists of an infrared laser transmitter unit and a receiver. The distance between the two components can be up to 200 meters. The function of the system is to provide detection of a targeted hazardous or flammable gas.

The basic operating principle centers around the selective absorption of specific wavelengths of light by the target gas. The transmitter infrared output is selected to match signature absorption patterns of the gas to be detected, with the receiver unit and its signal processing electronics tuned for the same signature. The output signal from the detector indicates the amount in target gas present in the beam path, which is proportional to the degree of absorption at the signature wavelength .

The Senscient ELDS™ incorporates advancements and technology that make its operation more resistant to the adverse effects of the operating environment and other less than ideal installation conditions than previous generations of open path gas detectors.

The included video provides more insight into the operation of the Senscient ELDS™ system. Share your hazardous and flammable gas detection challenges with process instrumentation specialists, leveraging your own knowledge and experience with their product application expertise to develop an effective solution.

Vortex Flowmeters

Multivariable vortex flowmeter combines flow, temperature
and pressure measurement into a single compact instrument
Image courtesy Krohne

Vortex shedding flowmeters provide process operators with consistent fluid flow rate measurements across a wide range of applications. These flowmeters measure the volumetric flow rate of steam, gas, and low viscosity liquids, boasting both versatility and dependability when used in conjunction with process systems.

Vortex shedding refers to the phenomenon wherein flowing gas or liquid form vortices around a solid object placed in the flow path. The measurement technology returns an indication of the process fluid velocity, which can then be used to provide volumetric or mass flow data. Vortex technology is well suited for many applications involving cryogenic liquids, hydrocarbons, air, and industrial gases. Vortex flow measurement requires contact between portions of the measurement instrument and the process media, so these flowmeters are commonly fashioned from a range of corrosion resistant materials.

The process of measuring the flow involves both the flowmeter and the ability for other instrumentation to measure the vortices themselves in order to calculate velocity. Ultrasonic sensors have become popular tools for measuring vortices. Applications involving flow measurement of high viscosity fluids are not suited for vortex technology because extremely viscous fluids do not behave in the same manner as lower viscosity fluids when their flow path is obstructed. Splitting higher viscosity fluids into concordant vertices is extremely difficult due to the internal friction present in highly viscous liquids.

Additionally, in order to split these process liquids, the piping through which the process material flows must be straight, and any disturbance or vibration in the pipe may impact the measurement. A vortex flowmeter will be in a fixed installation. This stationary element, operating without electrodes, can be advantageous for flow measurement in chemical applications utilizing low viscosity fluids.

The vortex shedding flowmeter is widely used for the measurement of steam flow. The high pressure and elevated temperature of steam, along with the variation that exists in most steam systems, have little negative impact on the operation of a vortex flowmeter. Vortex shedding flowmeters are often volumetrically based in terms of measurement, but their output can be combined with other fluid information to calculate mass flow. A product variant commonly available will combine the vortex flow measurement with temperature and pressure compensation, delivering three process measurements from a single installed device.

Share your process and flow measurement challenges with instrumentation specialists, leveraging your own knowledge and experience with their product application expertise.

Pressure Switch Design Details

Industrial process control applications present dynamic and varied requirements for measuring, monitoring and control. Each point calls for specific evaluation of the information needed from the process point for use in monitoring process performance, or control to be applied at the process point to regulate an outcome. Sometimes, a continuous analog signal is needed to provide indication across a range of values. Other times, it is only necessary to have notification of, or take action when, a certain temperature or pressure related event occurs. In those cases, a simple and reliable device can adequately meet the project requirements.

Pressure and differential pressure switches connect to a process and change their switch position when a setpoint condition is reached. The are simple to understand, easy to install, low in cost, and require little maintenance of attention. The switches are available in an extensive array of configurations, with options to fill out almost any application requirement.

SOR, Inc., globally recognized manufacturer of temperature and pressure switches, has produced this video outlining some of the distinctive features of their pressure switches for industrial process control applications. Share your process measurement and control requirements and challenges with product application specialists, and leverage your own process knowledge and experience with their product expertise to develop effective solutions.