Ultra-High Sensitivity Aerosol Spectrometer

The UHSAS-G is an optical-scattering, laser-based aerosol particle spectrometer for sizing particles in the 0.06 µm to 1 µm range. The instrument counts particles in up to 100 user-specified sizing bins, with a resolution as fine as 1 nm/bin. This high sensitivity makes the UHSAS-G ideal for aerosol research and filter testing.


Get accurate sizes for even the smallest particles, and eliminate sizing uncertainty associated with scattering spectrometers that measure at sizes larger than the excitation wavelength.

Categorize particles by size in up to 100 bins (user selects number of bins and boundaries), and count up to 3,000 particles per second.

Rely on the aerosol spectrometry technique with two detection systems: a primary, highly sensitive APD-based system to size smaller particles and a secondary PIN photodiode system to size larger particles.

Compensate for small drifts in laser power via automatic gain control.

Get an on-board computer, built-in monitor, and powerful LabVIEW-designed software for easy, real-time data analysis.

Particle light-scattering

  • A solid-state Nd3+:Y LiF4: ~1054 nm laser illuminates particles.
  • Scattered light is collected by two pairs of Mangin optics – highly sensitive APD-based system to size smaller particles, and a secondary PIN photodiode system for larger particles.
  • Amplification allows detection of particles as small as 60 nm.
Auxiliary Parameters Temperature
Derived Parameters Particle diameter
Number Concentration Range 3,000 particles/second
Particle Size Range 60 nm – 1 µm
Aerosol Medium Air, 0 - 30 °C (32 - 86°F)
Lasers Solid-state Nd3+:Y LiF4: ~1054 nm, 1 kW/cm2 intracavity circulating power
Pump Laser: ~797 nm, 1.6 W
Number of Size Bins 100 max:
99 standard bins (98 if both overflow and underflow are enabled)
One overflow bin and one underflow bin
Sample Flow Standard option: 1 – 100 standard cm3/minute (typically 50)
Other options available
Flow Control Controlled from software; can also be manually adjusted via mass or volume flow controller
Front Panel Display Built-in monitor, 2 USB 2.0 ports
Rear Panel Connections System power switch, system power connection, Ethernet, exhaust vent, exhaust port, serial stream connection
Computer System On-board Intel®Celeron™ CPU
504 MB RAM
80 GB hard drive for data storage
User interface via standard keyboard, mouse, and built-in monitor (included)
Software Executable program written in LabVIEW
Data Recording Output file written to computer hard drive
Output data sent to serial port
Communications Output Serial, Ethernet, USB
Power Requirements 100-240 VAC, 47-63 Hz, 200W
Dimensions 56 cm L x 43 cm D x 24 cm H
Environmental Operating Conditions Temperature: 0 – 30°C (32 - 86°F)
RH: 0 – 100% RH non-condensing
Altitude: Sea level to 4 km

Rack mountable unit (standard 19” instrument rack)
External laptop (for remote applications, replaces flat screen display)
Particle-by-particle (PBP) feature (supplies information on individual particles, including inter-particle times)
Bidirectional serial stream communication control

The Lifecycle Care Program ensures UHSAS-G integrity and performance vital to your research mission for 3 years or 3 calls (whichever comes first). When conducting complex and time intensive laboratory or field measurements it is critical to avoid down time, and ensure data collection accuracy. The program consists of 3 key deliverables for each year or call:

  • Instrument Logistics
  • Instrument Integrity
  • Instrument Performance

Lifecycle Care Program Includes:


  • Shipping to and from Droplet Measurement Technologies facility
  • Customs handling, including CARNET ATA if required


  • Incoming instrument evaluation and health check


  • Software and firmware validation
  • 100%-unit functionality test
  • Calibration data
  • Calibration report
  • Certificate of calibration

At times, our technician might discover an instrument issue, which might not be covered by the Lifecycle Care Program or by our product warranty. In such case we will reach out to you with a service & repair estimate to allow you to provide us with the next steps of action.