Mag meters are top of the line when used properly, drawbacks are they are expensive and require a constant source of power, most models will provide a 4-20 mA or 0-10 VDC signal, a pulse contact and a reverse flow contact (some brands the contacts are dry only through a relay) Power requirements are small and can be 24VDC or 77-250 VAC 50/60 Hz. Most brands are standard NEMA 4 with NEMA 7 available.
Follow manufactorers instructions for grounding and piping arangements.
Hydrae