ARTICLES

Water Meter-"The Cash Register" of Your System

by Jim Patton

One of the principal mistakes contrived by Utilities in selecting an AMR System is ignoring the WATER METER. The water meter serves as the common denominator or Watch Dog, if you will, of any successful water system. More importantly, the Water Meter is the only source of revenue generated by a water utility. In other words, it pays the bills. Yet, many today think of the water meter as a commodity, to be bought and sold as with chemicals, soap or other commodity type products. Contrary to this common credence, there are significant differences in water meters. Be mindful that an AMR system, with the latest & greatest electronic technology, is only as accurate as the water meter reporting.

Consequently, when evaluating and selecting an AMR system one ought to correspondingly assess in every aspect the performance, accuracy & (nationally published) warranty of the water meter independently from the AMR System. Such an endeavor will assure unmitigated long term accurate reading success for the utility.

Reality is that over 90% of the residential meters deployed in North America are Positive Displacement (volume metric) type meters versus Multi–Jet meters (inferential).

As simplistic as it may sound, there are virtually only three things (short of a sledge hammer) that affects a water meter. They are, Velocity (speed at which water passes through the meter), Volume (total amount of water displaced) and lastly the Quality of the water it is measuring.

Rest assured inorganic material in the water being measured, i.e. Magnesium (Mg), Calcium (Ca) and/or Iron (Fe) will over time take its toll on any water meter. Hence, an active meter maintenance program should be put into practice for both residential & commercial applications to ensure peak meter performance.   

Conversely, an inferential type of measurement, particularly in residential applications, can be likened to playing Russian roulette. Reason being, the paddle wheel spins freely & by no means does one know where it will stop. The Multi-Jet is subject to hydraulic creep or what’s commonly known as “coasting” due to surges or rapid actuated valves, i.e. washers, sprinkler / irrigation systems.

Likewise, fast start ups with the multi-jet can create a jetting condition which lends itself to an over-under registration condition.  Keep in mind, as with all inferential type meters, the same requirements for straight pipe diameters up stream & down stream applies regardless of meter size. Be wary if you are installing Multi-Jets with meter setters, yokes or elbows (90 degree) applications. Otherwise, you’re subject to gross inaccuracies.

Why risk it, go with the tried & true to indemnify equitable water distribution to your customers and sustain the integrity & accuracy of your water system.

That being said, the 90% of the utilities that stipulate Positive Displacement meters across the fruited plains can’t be all wrong?  We at Avanti welcome an opportunity to discuss any issue relative to your metering needs.

Jim Patton has 32+ years experience in the industry promoting water meters and automated reading systems.  Please feel free to contact us  to leverage this experience.