Pulse Output Water Meters
Overview and Selection Guide

When it comes to water meters, a pulse output is simple SPST (single pole, single throw) dry contact reed switch. The switch is normally open. The switch closes when a magnet is in close enough proximity to pull the reed to the closed position. The magnet is positioned on a dial (or drum in some cases) that rotates due to water flow. When the magnet travels far enough away, the reed is released and the switch opens. The closure and opening of this switch is a single "pulse." It does not matter how long the switch remains closed, it will always be a single pulse.

Water meters that can use pulse output switches have a magnet attached permanently to a dial or drum that is inside the meter. The most common pulse output switch attaches to the lens of the meter's register, directly above a dial that has the magnet attached. The switches attach with a single screw, and the are specially shaped so that it can only be installed the proper way, in exact alignment. Certain meters allow for a choice of which dial to use for the pulse output, thus determining the volume of water that is represented by a pulse. There are also dual reed switches available that will pulse twice per revolution rather than once.

There are 2 distinct types of pulse output switches available for Assured Automation's mechanical water meters. Only the correct switch type is offered when buying any meter, so you need not worry about selecting the proper type. Simply check the "Include a Pulse Output" checkbox while configuring your meter.

These switches can also be retro-fit as an upgrade at a later date.