For many, a particular benefit is the ability of these meters to be installed virtually anywhere. Tim Door, Global Product Manager – Magnetic Flow, ABB Stonehouse, explains the benefits of buriable electronic meters and how advances in technology are opening up new possibilities in the way operators can collect and manage flow data.
Flow metering technology has come a long way in the last 15 years. Advances in technology have seen electronic flow meters steadily outstripping their traditional mechanical counterparts in everything from accuracy through to the total cost of ownership.
The inherent robustness of electronic flow meters, coupled with advances in communications and in-situ calibration technology which rule out the need for direct contact with the actual meter, has seen them being used in an increasing number of direct burial installations.
The case for burial
The ability to bury a flow meter is advantageous for a number of reasons. Foremost amongst these is the cost of installation. In the past, a conventional meter installation has required installations to incorporate a chamber for housing the actual meter, plus pavement furniture and ancillaries such as valves, strainers and extra pipework. In this case, for every $1,000 spent on a flowmeter, $4,000 is spent on installation.
ABB’s AquaMaster flow meter rules out the need for everything other than the meter primary and an accompanying transmitter, which in the case of ABB’s Explorer submersible transmitters, can also be installed underground in a small chamber. Not only does this reduce the cost of an installation by an average of around 60%, but it also substantially reduces the amount of time and disruption caused during the installation process, particularly ideal where a meter is being installed in a busy thoroughfare.
Furthermore, locating the transmitter underground rather than in an enclosure above ground also offers additional protection against damage caused by vandalism.
These benefits have been further amplified by the arrival of SMS communications technology, which has opened up a wealth of possibilities for where an electronic meter can be installed. Starting about four to five years ago, the water meter data logging market in the UK underwent a quiet revolution with the introduction of SMS, text message based, data transfer. With the integration of SMS communications into the measuring instrument, remote operation, configuration, datalogging and maintenance have all become possible.
Remote SMS enabled programmability has highly significant and far reaching implications not just for the quality of the data, but for the manner in which the meter stock may be managed, and especially for the management and distribution of flow data. It allows alterations to be made to the configuration of the instrument after installation, such as changing the power mode of the meter for the purposes of achieving enhanced performance. It enhances maintenance by offering performance and condition monitoring throughout the equipment’s life with options such as programming the meter to send an alarm out in case of problems.
Most significantly, remote programmability has eliminated the need for a meter field technician to visit each meter location to manually download flow data. Instead, operators can now achieve all of the manual operations electronically, using a single, once a day text message.
Problems with powering these meters in remote locations have been overcome by the introduction of battery technology offering comparable performance with mains power. The batteries used in ABB’s AquaMaster, for example, now offer a greatly prolonged lifespan of up to 5 years, minimising the need for battery replacement.
Taken together, these features substantially reduce life cycle costs and provide operators with an almost ‘fit and forget’ device which requires minimal direct intervention throughout its life. So a battery-powered AquaMaster with SMS and Explorer transmitter need theoretically only be maintained once in a 5 year cycle, enabling a true resolution to a reduction in whole lifecycle costs.
New data management possibilities
For meter technologists and engineers, the acquisition of accurate meter data has often been wrongly viewed as an end in itself, rather than as a means to an end. In fact, the economics of collection, collation, analysis and then accurate distribution of meter information to the relevant parties within management can often be as important as the front-end equipment.
For the “standard” user it is unlikely that much more will be demanded than that which is currently available from the independent data loggers widely used throughout the UK. However, there are some applications that require more sophisticated flow metering technology.
One example is where precise measurement of flow rate is required, such as night time flow analysis. Whilst most water companies are interested only in metered volume, for which logging of discrete pulses is adequate, flow rate is essential when the role of the data demands that flow events over a given time are measured. The classic example is for night time flow analysis, where it may not be apparent which components are due to loss of water from the pipe and which are attributable to short term events such as tank filling by industrial customers.
With the advent of SMS logging, the user can choose how often data is captured and transmitted to get a clearer picture of flow events. For example, with a meter based upon rate, such as electromagnetic designs, it is possible to observe a whole range of events within the water distribution network which were previously obscured by the averaging effects of slow, pulse derived, pseudo-rate data.
Data Quality & Traceability
The Environment Agency (EA) is developing guidelines for all buried electromagnetic meters which will require users to demonstrate traceable evidence, which is accurately collected using independently calibrated equipment. The aim is to create a verification record database that can be objectively analysed and securely archived to achieve a single metering installation uncertainty, which can be subject to periodic independent review.
New in-situ verification and calibration technology, such as ABB’s CalMaster2 Iris, enables users to comply with future legislation like this without removing their meters from service. This technology can remotely verify calibration of the sensor and transmitter and verify the continuity and integrity of the sensor and transmitter cable without ever having to excavate the flow sensor, making buriable meters an even more attractive proposition.
Conclusions
Flowmetering technology has improved tremendously over the past few years and continues to do so. The new additions to buriable electronic meters with SMS capabilities and in-situ verification and calibration systems, coupled with their inherently lower cost of installation and reduced lifetime cost, continue to make them an ever more attractive alternative to conventional mechanical metering technologies.