Flow/No Flow Controllers and Sensors

Designed to sense and indicate material flow, or the cessation of material flow, in conjunction with an Acrison feeder, Acrison’s accurate and reliable Model 800 Flow/No Flow Sensor utilizes Doppler Technology for sensing material flow/no flow. Typically installed in the right angle downspout of an Acrison Dry Solids Feeder, a low energy signal is transmitted by the flow/no flow sensor into the flow stream of material as it discharges from the feeder. Some of this signal is reflected back to the sensor with a frequency shift caused by movement of the discharging material. This frequency shift is called the Doppler Shift and is used by the sensor to determine whether or not material is flowing.

An adjustable time delay, variable up to fifteen seconds, is accessed from the Model 800A Flow/No Flow Controller to allow a user to set the amount of time that lapses after a cessation of flow has been detected before an alarm is given.


  • Durable and Dependable – virtually unaffected by humidity, pressure, vacuum, temperature, and non-metallic build up or dust
  • Adjustment-Free Sensor – sensor is adjustment free and rated intrinsically safe when connected to its control unit (Class II, Groups E, F, and G)
  • Self-Monitoring Controller Console – includes a switch-selectable fail-safe alarm should the unit lose power, and a fault indicator for loss of communication with the sensor


Flow/No Flow Controllers and Sensors Specifications:

  • Model 800 Flow/No Flow Sensor – NEMA 4 aluminum enclosure rated for operation over an ambient temperature range of -22° to 158°F. Emission is 24.125 GHz, less than 1mW/cm2. Conduit connection is ¾” NPT
  • Model 800A Flow/No Flow Controller – flange mount, 8” x 6” x 4” NEMA 4, 12 and 13 fiberglass enclosure rated for operation over an ambient temperature range of -31° to 158°F
  • Power Requirement – 115 VAC, 50/60 Hz, 5VA. Output contacts (DPDT) rated at 5A @ 240 VAC or 30 VDC. Requires five-conductor shielded cable for connecting to the Model 800 Flow/No Flow Sensor