When Minnegasco implemented a load study to prove conservation techniques, they planned ahead for consultants, electronics, budgets, and software analysis. The meter interface itself, however, was selected in the final planning stages. That didn’t present a problem because retrofit pulsers are available for most residential and commercial gas meters. They chose a retrofit pulser that mounts under the meter index cover, a unique feature that delivers a number of benefits, including application flexibility. This high-resolution pulser helps bridge the gap between bottom-line performance expectations in load studies and commercial and residential AMR projects.
Roger Dissmeyer, Minnegasco’s gas measurement/gas control supervisor, was involved in the choice. “We’re always looking for a product that offers a lower cost — that’s the bottom line. For our project, we specifically required a flexible pulser that would provide a pulse our recorder could handle. RIOTronics’ RegistRead delivers the accuracy and flexibility we needed at a lower cost.”
Minnegasco chose the Schlumberger Industries as the project’s prime contractor for the equipment acquisition and installation. Ken Prevatte, Schlumberger’s utility services group manager, supervised the project team assigned to Minnegasco. From his vantage point, the flexible retrofit pulser was a key element. According to Prevatte, “This pulser stood out in our minds from the beginning. It is adaptable to several kinds of commercial and industrial meters. This was important because we had meters representing a variety of vintages and vendors. When the project team needed a way to work with meters without instrument drives, we were able to use RegistRead in our retrofit solution. Ultimately, with the use of our retrofit adaptor, RIOTronics was able to fit dial indexes for the rotaries without instrument drives. The pulser provided a special index cover for the commercial Rockwells, so the pulser stayed under the index cover and out of the elements. This pulser was the most economical choice for getting pulse information off the meters.”
Dan Hack, the on-site project manager, says, “The most critical path for the study was the implementation deadline. It was and extremely tight timetable and the pulser supplier demonstrate exceptional supply sensitivity. Because we were working with so many different meters, we had to order a variety of configurations, as well as some odd parts.”
How it works
The pulser consists of a durable permanent magnet rotor on the reading dial or test dial, and a custom Form-A switch. The high resolution unit provides either 2 or 10 pulses per revolution of the index dial to the majority of AMR, data logging, display equipment, and recorders. Any meter reading or recording device that accepts dry contact, contact closure, Form A, Form C, or KYZ inputs can be used with the device to provide a meter connection. The pulse is reported to be the most affordable device available today for retrofitting gas meters.
The unit is easy to install. That’s another area that was important to Dan Hack. “We had very little downtime. Once we’d installed a few, we had it down. We had some concerns initially with the epoxy, but it hasn’t been an issue. The epoxy has performed well.”
The manufacturer ships the structural adhesives needed for installation with the product. Made up of an aerosol spray and the epoxy itself, the adhesive is so strong that removing a pulser from the index means taking the ceramic coating with it — right off the face of the index.
The pulser’s under-the-index-cover design incorporates tamper-proof housing and electronics, while providing protection from outdoor temperature extremes. These features help generate cost savings — especially with customer tampering and diversion of services on the rise. Some utilities report up to 4% of their meter consumption stolen.
The pulser was specially designed to address — and thwart — tampering. The patented metal case around the switch acts as a shield to protect the switch from strong magnets sometimes used to stop the pulse switch. If a thief attempts to cut or short out a wire, electronics in the pulser can interact with the meter reading device or recorder to instantly recognize the intrusion and report it as an alarm to the central office. For those utilities needing more flexibility or customization within their tamper alarm programs, serial and parallel resistors give the pulser a dozen or more custom versions for various recorder and AMI companies.
Current demand for tighter accountability from today’s customers will continue to bolster the need for pulsers. In anticipation of this growth, RIOTronics has developed a dual-switch customer pulser. This pulser unit has a second switch assembly on the meter index adjacent to the utility’s switch to ensure that the customer’s pulse is identical to the utility’s pulse. The pulse is double-sealed in glass and epoxy potting, so it can’t create a spark. That design feature. combined with the pulser’s very low outside power source requirement — typically 5 to 12 volts at under 100 microamps — means the pulsers don’t need a safety barrier. The pulse unit if considered so safe that Canada waived CSA safety approval when if conferred Industry Canada approval.
Customer need supplied the impetus to create a dual-pulse product. In this case, the customer was Xcel of Colorado. When the utility discovered the need for a dual-pulse product, RIOTronics was able to develop one.