Meteorological Particle Spectrometer (MPS)


An optical disdrometer that measures the size distribution, fall velocity and rain rate of droplets from 50 µm to greater than 6.4 mm.
Special feature: 2-D particle images




  • Rain research
  • Drizzle research

The National Weather Service uses the MPS for precipitation studies.


  • Provides 2-D imaging of precipitation particle sizes and shapes
  • Provides 1-D histogram of particle sizes
  • Features high-speed serial RS-422 or RS-232 interface
  • Features all-weather enclosure 44 cm (L), 44 cm (H) and 18 cm (W)
  • Includes w ind vane to align sample path with wind flow
  • Includes free-standing swivel-mount (post not included)



The Particle Analysis and Display System (PADS, right) is optional software that provides a user-friendly virtual instrument panel.

PADS allows the user to control the MPS and display real-time data and logs. For instance, the program enables the user to do the following tasks: 

  • Sample and record data
  • View particle volume and number concentrations, as well as Median Volume Diameter (MVD) and Effective Diameter (ED)
  • View LWC as measured by the MPS
  • Monitor instrument parameters like MPS laser current and various electronics voltages
  • Play back data for post-flight viewing
  • Reprocess data with new parameters for additional analysis

Online MPS Software Manual




Parameter Specification
Measured Parameters Single-particle light imaging
Derived Parameters Particle diameter

Particle number concentration

Liquid water content (LWC)

Effective diameter (ED)

Median volume diameter (MVD)
Technique 64-element diode array, 20-cm path length
Resolution 25, 50 or 100-micron resolution (specify when ordering)
Particle Size Range 50 µm to >6.4 mm (maximum size depends on probe resolution)
Number Conc. Range 0 - 2,000 particles/cm3
Particle-by-particle Fall Velocity 5 - 500 cm/sec
Inter-arrival Time of Particles 0.001 - 100 sec
Calibration Verification Spinning Disk
Communications High-speed serial RS-422 or RS-232 interface
Software Optional PADS software provides data analysis tools to display, record and play back data
Power Requirements Powered by 115 V / 60 Hz or 230 V / 50 Hz (specify when ordering)
Power consumption: 200 W

Specifications are subject to change without notice.



Included Items

  • Instrument
  • Test cables
  • Spinning disk (pictured at right)
  • Shipping case
  • Operator Manual
  • One-year warranty
  • One day of training at DMT facility
  • Email and phone technical support

Accessories (Purchased separately)

  • PADS software and laptop
  • Optical Array Shadow Imaging Software (OASIS)



How to Order

Contact DMT for pricing or more information.


Phone: +001 303 440 5576
Fax: +001 303 440 1965