A large national sewage company’s consultant contacted EESIFLO for the measurement of RAW sewage pipes using clamp on transit time flowmeters. A test was requested to see whether or not clamp on meters could replace the very expensive alternative of using inline technology. An EESIFLO technician was dispatched at 9 .am in the morning to perform clamp on transit time measurements. Although able to measure the flow in the large pipe, he noticed that at this time the signal strength was exceptionally weak and so he waited for several hours to see what would happen during higher flow rates at times when more sewage was being discharged or when it was raining. During the lunch hours, the signal was lost completely and it was evident that the pipe contained large amounts of suspended solids with air bubbles trapped in the solids moving through the conduit.. This was a perfect chance for a Doppler meter application so he requested the opportunity to install a portable clamp on Doppler meter and so the EASZ-10FP was installed and was able to measure both lower and higher flow rates. The specifications were then modified to accommodate clamp on fixed meters for this particular application.

The EESIFLO 3000 Series Doppler unit simply requires the user to input the pipe’s internal diameter. The EESIFLO meter then sends diagnostic signals through the pipe wall and into the liquid at a fixed frequency normally under 1 MHZ. The signal reflection strength and other factors will then determine whether or not a Doppler measurement is plausible. The signal propagation cannot be interfered with by users. This prevents the 3000 series from being mis-applied on clean clear water applications where Doppler units have been terribly mis-applied in the history of clamp on flowmeters. The EESIFLO EASZ-3000 has been developed to work within a “sober” velocity range of 0.3 to 10 m/s and and requires a minimum amount of “reflectors” to operate. Hand held Doppler test units can be initially supplied to users who wish to investigate the plausibility of using clamp on Doppler flowmeters in their applications before purchasing multiple fixed units running on 110/220 VAC. The EASZ-3000 also has a standard 4-20 mA, pulse and relay outputs which can be sent to a DCS or control system for remote viewing. The sensors are potted for extra protection and the Aluminium powder coated transmitter case is rated to Ingress Protection 66. Standard 3000 series meters are supplied along with a stainless steel external pre-amplifier which allows the user to extend the sensor/transmitter distance by 300ft or more using standard signal cable available in most areas of the world. The pre-amplifier allows the user or consultant to forget about cable distances during purchase since it is sometimes very difficult to determine actual cable lengths before installation.

The EESIFLO EASZ-3000 flowmeter has been installed in major plants around the world including Sewage and Sludge applications, dredging and sandy water, liquids with suspended solids , all manner of mines and mining applications, aerated liquid media and more. Contact your local EESIFLO direct office or representative for more information on price and availability of the portable or fixed versions of our microprocessor based Doppler flow meters and controllers or log onto www.eesiflo.com