The Electronic F-Series Flow Monitor

The F-Series flow monitor is used in conjunction with all flow control assemblies. The F-Series is a flow transducer that measures compressed gas flow rates. This measurement is made with a differential pressure transducer. P1 measures the input pressure of a Venturi and P2 measures the pressure in the throat of the Venturi. The difference in these two measurements is used to calculate the actual flow through the F-Series. Utilizing an all analog circuit results in an extremely fast flow detection of less than 10ms, in most instances. This high speed functionality also allows the F-Series products to be used in conjunction with Proportion-Air’s proportional regulators for compressed gas flow control. To ensure high speeds, the F-Series products use analog electronics internally for signal amplification and calibration. All F-Series products are mass flow (implied) measurements.

The F-series flow monitor is available in 3 different models:
FR (pressure regulated), FP (pressure compensated) & FA (atmosphere)

All three flow monitor models have the below specifications in common:

  • Response Time: < 10 milliseconds
  • Port Size: 1/4″ to  1-1/2″ NPT or BSPP
  • Durability: Immune to shock & vibration (up to 20 Gs)
  • Operating Temps: 32-158°F (0-70°C)
  • Output Signals: 0-10 VDC or 4-20 mA analog output
  • Media: Calibration to a variety of inert gases
  • Lowest Flow Range: 2-20 SCFH
  • Highest Flow Range: 25-250 SCFM
  • Digital Display Available: Yes
  • Repeatability: +/-0.25%

FR Series Pressure Regulated Flow Monitor

F-Series Flow Monitor w/Digital Display Option

Requires a known and regulated inlet pressure

FR-Series | This F-series flow monitor is a pressure regulated mass flow transducer which provides flow measurement in real time, less than 10ms. This model requires a known and fixed regulated supply pressure to maintain its calibration. By regulating the input pressure, the incoming density of the gas is known and the FR model output is calibrated for that density.

FP Series Pressure Compensated Flow Monitor

F-Series Flow Monitor

Compensates for fluctuations in supply pressure

FP-Series | This F-series flow monitor has a 2nd transducer that measures the absolute pressure of the incoming gas. This allows the unit to compensate for changes in gas density due to changes in pressure. The FP model can compensate from 50 to 100% of the maximum calibrated absolute supply pressure, as called out in the part number.

FA Series Pressure to Atmosphere Flow Monitor

F-Series Flow Monitor

Meters out gas to control the speed of cylinders 

FA-Series | This F-series flow monitor must have its output port open to atmosphere in order to work properly. It is calibrated for the density of gas at atmosphere. The FA model is most commonly used to meter out gas in cylinder speed control applications. The FA model must be paired with an FQPV, FQB3 or FQB2 to control cylinder speed.


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