Miniaturized Scanning Electrical Mobility Sizer Model 9404


Fast electrical mobility-based aerosol number size distribution measurements in a compact package. The miniaturized Scanning Electrical Mobility Sizer (mSEMS) allows you to perform ultra-fast particle number size distribution measurements on-board Unmanned Aerial Vehicles (UAVs) and other mobile platforms where high time resolution is critical. The rapid time response is the result of a miniaturized differential mobility analyzer design coupled with the 0.18 sec response time of the aMCPC detector. Capable of scan times down to 5 seconds and a scan size range between 5 and 375 nm, the system is compact, light and uses minimal power.

The size range may be extended to 560 nm diameter with an upgrade to the high voltage power supply.

The size range has been optimized to provide a 200 nm overlap with the Model 9405 mOPC. Development of the mSEMS is built upon BRECHTEL’s decades of experience with traditional SEMS instruments and UAV/aircraft field studies. Deploy the 9404 in conjunction with our other portable instruments to get a more complete picture of your particle sample.

Learn About Product

All Features
  • 5 to 375 nm particle size range (extendable to 560 nm)
  • High size resolution
  • Compact, lightweight, low power use
  • Rapid scan times down to 5 seconds
  • Fast-response aMCPC detector
  • Good size overlap with Model 9405 mOPC
  • Self-contained operation with on-board data storage
  • No external pumps required
  • Minimal count smearing due to ultra-fast aMCPC response
  • Fast scan times match needs of mobile and airborne platforms
  • Robust aMCPC design minimizes butanol flooding problems
  • Easy-to-clean DMA design and overall instrument maintenance
Technical Specs

Copyright ©2024 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
  • Mobile platform sampling: UAVs, Balloons, Aircraft, Vehicles
  • Personal exposure monitoring
  • Climate change field studies
  • Air quality monitoring
  • Aerosol-cloud interaction studies
  • Wildfires, Climate & Health
Integrated firmware drives each ACCESS module from the inside – the built-in microprocessor and sensors are able to sense, control, and report on instrument performance. A serially-communicated stream of data provides real-time user access to operating parameters and measurement values. An on-board micro-SD card can be used to store data locally.
Add the Model 9400 Base Module option with the UAV Reader software to your ACCESS package to benefit from a graphical user interface (GUI) that allows you to easily interact with the instrument and view measurements on the screen of the mini-PC. Multiple ACCESS modules can be connected via a micro-USB hub to easily change the system configuration. The 9400 also allows each of the connected modules to be remotely controlled via a single RS232 connection.
The UAV Reader software automatically recognizes which instruments are attached to the Base Module and adjusts accordingly. It is provided to facilitate configuration and monitoring of the ACCESS instruments on the ground and during mobile sampling, but is not required to operate the unit.

The mSEMS firmware is capable of performing the full range of sizing scan control and stores the raw, uninverted scan data on the local SD card. However, if the mSEMS is operated without the 9400 Base Module and UAV Reader software, the raw data will require post-processing using the Igor™ software program provided by Brechtel. If the mSEMS is operated with the UAV Reader software then data processing is completed in real time during acquisition and no post-processing is required.

What's Included

• Model 9404 mSEMS (includes aMCPC)
• LED Displays for sizing module and aMCPC
• External 12 VDC power supplies for sizing module and aMCPC
• Communication and power cables
• Ship kit
• Operator’s manual
• Weatherproof shipping cases


The following optional accessories are available:

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