Isokinetic Inlet System

Model 1200


Sampling particles from moving platforms can be tough – especially larger coarse-mode aerosol that are easily lost inside inlets due to turbulent deposition. The Isokinetic Inlet System has been designed using our wind tunnel facility to minimize particle losses in aircraft sampling applications where automated operation and field-tested performance are required. Brechtel has over 14 years of aircraft sampling and isokinetic inlet development expertise to help with your application.

  • Fully automated, hands-off operation
  • Transmission efficiency > 90% for particle aerodynamic diameters < 10 microns
  • Wind tunnel tested and validated
  • Custom inlet manifold design for each application including sample pickoffs
  • Custom mounting solutions that account for aircraft angle of attack
  • Aerodynamic, twin-diffuser prevents turbulent boundary layer separation
  • Passive pumping removes diffuser turbulent boundary layer
  • Low power blower to draw and actively control 150 lpm sample flow (up to 100 lpm of air flow for instruments)
  • Anti-icing system


  • Passive pumping in diffuser reduces necessary pumping power
  • Small rack-mountable control chassis easy to integrate
  • Easily adaptable to different aircraft
  • External probe design that has passed FAA review
  • Automatically maintains isokinetic flow using built-in air speed measurement

Technical Specs

Isokinetic Inlet System Tech Specs

parameter value
Particle aerodynamic diameter size range 0.005-10 μm
Sample flow at diffuser tip (@100 m/s) 300 lpm
Sample flow to cabin 150 lpm
Maximum sample flow to instruments 100 lpm
Control and DAQ frequency 1 Hz
Anti-icing power (supplied by platform) 900 watts @ 28 VDC
Rack-mountable electronics chassis size 19 x 6.5 x 12 in/48.25 x 16.5 x 30.5 cm
Electronics chassis weight 20 lb/9 kg
Total system weight 70 lb/31.75kg
Operating temperature range -40 to 45°C
Operating pressure range (absolute) 200-1,000 mb

Copyright ©2017 All specifications are subject to change without notice. BMI assumes no responsibility for inaccuracies in this document or for any obligation to update information in this document. BMI reserves the right to change, modify, transfer or otherwise revise this publication without prior notice.

*Some products may be shown with optional accessories, which are sold separately. Items shown may not be to scale.

Applications and Solutions

  • Plume studies of power plants
  • Megacity plume studies
  • Volcanic ash studies
  • Below cloud aerosol studies for cloud condensation nucleus research
  • Visibility reduction studies
  • Climate change research
  • Vertical profiling of aerosols
  • Air quality research
  • Mobile laboratories


The ISO inlet operating software provides real-time displays of current parameter values, including Air Speed, Tip Volume Flow, Measured Volume Flow and Volume Flow Setpoint. You can quickly change the total instrument sample flow drawn from the sample pick off ports and the control software will automatically adjust the amount of flow needed to maintain isokinetic sampling conditions. Operating pressure and various temperatures are monitored to maintain proper flow and anti-icing system control.

Two distinct flow control modes are available: direct flow control by varying the speed of the built-in high speed blower, or flow control using the blower coupled with a low pressure drop control valve. The two techniques broaden the dynamic pressure range over which the system can be operated. Control software is built into the micro-controller inside the control chassis, so no external PC is required to operate the system. Graphical user interface (GUI) software is provided to run on a user-supplied PC. The PC must be running Windows 7 or later system software and have at least one free USB port. The GUI provides timeline plots of all major operating parameters and allows key system settings to be easily changed.

What’s Included

The Model 1200 ISO Inlet comes with the following items:

  • One external sampling probe assembly with mounting plate & anti-icing
  • An inlet manifold with two pick off port assemblies for instrument sampling
  • Rack-mountable electronics chassis
  • Interconnect cables and tubing with user-specified lengths based on installation needs

Note: It is the customer’s responsibility to physically mount the ISO inlet to their aircraft or other platform.


The following optional accessories are available:

Isokenetic Accessories

Part Number Description
ISO-SP025 Sample pick-off port with 1/4" OD tube
ISO-SP0375 Sample pick-off port with 3/8" OD tube
ISO-SP05 Sample pick-off port with 1/2" OD tube
ISO-90 Ninety degree bend for 1.5" OD main sample manifold line at mounting plate
ISO-Kit Maintenance Kit for 1200 ISO

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Contact us to discuss how Brechtel can help you.