The SM series devices can be fitted with set point switches triggering on flow rate. These are mounted externally in a protective housing, and are actuated by a magnet in the float. This same
magnet can also be used to couple to an external flow indicator, allowing reading of flow rate without requiring visibility of the float. This allows the SM...to benefit from all the advantages inherent in using an all metal construction (high pressure, shock resistance). The instruments are designed to handle flow rates much larger than their stated maximum flow range without damage. At excessive flow rates the device will, however, induce a larger pressure drop.
