AS-FS Flow Sensor Dual Output

FCI’s AS-FS Dual Output flow sensor provides fully redundant and separate outputs in the same outline dimension envelope of single sensor output designs. This is achieved by employing two electrically independent sensor heads and circuit boards; the second output assures continued operation in spite of a failure of one of the two redundant channels, thereby reducing the probability of an erroneous low flow or dry signal caused by a single sensor failure.


  • Liquid Cooling Systems
  • Fuel Transfer
  • Fuel Tank Inerting Systems
  • Lubricating Oils
  • PACK Air Systems
  • Hydraulic Fluids
  • Bleed Air Systems
  • Ground and in-flight refueling


Service: Flow monitoring of liquid or gas.

Material: Wetted parts 316 stainless steel, all welded construction

Electronics Enclosure: Hermetically sealed units; 316 stainless steel

Electrical Connection: D38999 or compatible

Process Connection: Flanged with O-ring seal

Insertion Length: Per customer requirement

Output Options
  • Flow Signal: Source 240 mA at 28 Vdc
  • No Flow Signal: Source 0 Vdc
  • Flow Signal: Source 0 Vdc
  • No Flow Signal: Source 240 mA at 28 Vdc

Open Collector
  • Flow Signal: Closed, sinking up to 100 mA at < 0.5 Vdc
  • No Flow Signal: Open, leakage < 10µa at 30 Vdc
  • Flow Signal: Open, leakage < 10µa at 30 Vdc
  • No Flow Signal: Closed, sinking up to 100 mA at < 0.5 Vdc

Electrical Power Input: 28 VDC nominal per MIL-STD-704

Power Consumption: 3 watt maximum

Weight: 8 oz. [227 g] maximum

Operating Pressure: Standard up to 2000 psig [138 bar (g)]; higher pressures available by request, contact FCI

Switch Point Adjustment
Factory set at customer specified switch point within flow range listed:
Flow Range
Process Fluid Switch Point Range
Air 0.25 SFPS to 1,000 SFPS [0.07 MPS to 305 MPS]
Fuel, Hydraulic Fluid, Coolant 0.01 SFPS to 10 SFPS [0.003 MPS to 3 MPS]
Water 0.01 SFPS to 5 SFPS [0.003 MPS to 1.5 MPS]
Operating Temperature Range
Flow Element: - 65 °F to 500 °F [- 54 °C to 260 °C] Specify actual requirement
Electronics: - 40 °F to 257 °F [- 40°C to 125 °C]

Repeatability: ± 2% of full signal range

Time Response: 1 to 10 seconds typical, depending on fluid type and switch point

EMI and Lightning Protection: MIL-STD-461 and RTCA/DO-160

Qualifications: MIL-STD-810 and RTCA/DO-160

Quality Systems Approval: ISO 9001, AS9100