Onicon recently update their turbine meter line, to include some nice digital features.
Among the goodies:
1. The ability to "flash" meters in the field, including changing pulse rates, pipe sizes, and analog output scaling. This makes it a lot easier to fix things with limited disruption to your project--- like if the actual flow rates are way higher than you expected and are pegging the output at full scale!
2. The F-1210 now includes an isolated analog output, where the signal common and power common are not connected. This can be a benefit in some installations where you are trying to isolate electrical noise, keeping the power common off the signal common is a typical remedy.
But what if you are replacing an old F-1210 meter (3-wire connection) with a new one that has 4-wires and you don't want to pull another wire? Its fine to connect the commons at the meter junction box, see pictures. This also works for F3500 meters as well.
For new installations, try to pull at least 4-conductor if you can so you have the choice to keep the signal common isolated.
As always please call us if you have any questions.