Compound Meter: Neptune
Compound meters were originally designed for industrial use, so that water utilities could capture very low and high water flow. Years ago, industrial water meters measured high water volumes well, but had trouble detecting low water flows associated with a toilet flushing or washing your hands. Although commercial 2″ meters’ accuracy has improved over the years, compound meters still find their way into heavy residential and industrial use. The Neptune meter shown above has a high flow side on the left and a low flow side on the right.
Before the advent of modern radio-read meter systems, these meters were manufactured with one unique meter number and the two heads. In our AMR system, one of these meters will require a dual-channel ert (endpoint). One channel will handle low flow, while the remaining channel will cover high flow.
Fortunately, the more modern meters come through with two meter numbers, which makes tracking them much easier.
Above is the high flow side of a compound meter. The low flow side’s meter number is missing the 70 prefix. So two meter entries can be linked as a compound meter but retain meter uniqueness within a billing or meter reading system.