• Hedland® flow transmitter flow alert switch

Hedland® flow transmitter flow alert switch

for fluids, air and compressed gases


  • No flow straighteners or special piping required
  • Relatively insensitive to shock and vibration
  • Automatically signals alarm, if flow is too high or too low
  • Installs in any Position
  • No mechanical linkage
  • Easier-to-read linear scale
  • Special scales available
Chemical/Petrochemical media, Gas, Water, Oil
max. flow:
from 0.1 up to 560 l/min
from -29 up to 116 °C
max. pressure:
from 0 up to 414 bar
Water & waste water industry, Chemical industry, General industry, Gas industry, Automotive industry, Aerospace industry, Oil industry


General information

The flow alert switch flow meters are rugged, longterm variable area flow meters for measurment of flow volumes. This product provides a local flow indication and automatically signals the operator or PLC if flow is too high or too low. Special scales are available according to customers request. Flow alert flow meters are available in single switch, double switch, reed switch and micro switch versions. There is no need for flow straighteners or special piping requirements.

Measuring principle

Variable area flow meters

Variable area flow meters

The variable area flow measurement method allows fluids (liquids and gases) volume streams to be determined. A moving sharp-edged orifice is located within the piston assembly, forming an annular opening with the contoured metering cone. The piston assembly carries a cylindrical PPS/ceramic magnet that is magnetically coupled to an eternal indicating magnet, which moves precisely in direct response to movement of the piston therefore providing a visual display of the flow rate.