Precipitation Imaging Probe

The PIP is an optical spectrometer that measures the size and shape of particles from 100 µm to 6200 µm.


Get specific measurements with range that is optimized for rain, snow, graupel, and hail particles.

Easily identify particle types by generating high-quality images via 64 photodetectors.

Reduce particle artifacts with open path format and anti-shatter tips.

Particle imaging

  • Shadow images of particles passing through a collimated laser beam are projected onto a linear array of 64 photodetectors to determine presence of particles.
  • Particle images are reconstructed from individual “slices,” where a slice is the state of the 64-element linear array at a given moment in time.
Parameter Specification

Optical Array Probe with 64 elements: 62 sizing elements, end diode rejection

Measured Particle Size Range

100 µm – 6.2 mm

Sample Area

260 mm x 6.2 mm for standard configuration (no Korolev tips)

Upper Concentration Range

100 particles/cm3

Air Speed Range

10 – 200 m/sec

Number of Size Bins


Sampling Frequency

Asynchronous, 0.1 – 10 Hz. 1-second sampling is typical


660 nm

Data System Interface:

Two channels: RS-422: 56,000 Baud Rate; High-Speed Serial: 4 x 106 Baud Rate (RS-422 only)


21 lbs./9.5 kg in DMT canister
10.5 lbs./4.8 kg outside of canister
25 lbs/11.4 kg with generic canister

Power Requirements

28VDC 3A for System Power
28VDC and 9A for Anti-ice Power
Optional AC voltages for system power and anti-ice heaters

Environmental Operating Conditions

Temperature: -40 °C to +40°C
RH: 0 – 100%, non-condensing
Altitude: 0 – 50,000 ft / 0 – 15 km

PADS software and laptop
Data Acquisition System

Droplet offers a three-year service plan to ensure that your PIP continues to deliver high-quality data. This plan locks costs upfront at the time of funding application and covers annual calibration, alignment, cleaning, wear-item replacement, calibration documentation, and shipping. Specific services provided for the PIP include:

  • Shipping to and from Droplet facility for service
  • Incoming instrument evaluation and health check
  • Optics cleaning and alignment
  • Temperature sensor calibration
  • O-ring replacement
  • Hardware replacement
  • Baseline voltages set and verified
  • Heater testing
  • Laser alignment
  • Calibration of instrument using spinning disk calibrator
  • Pitot calibration
  • Software, firmware, and antivirus update
  • Canister test
  • 100% unit functionality test
  • Calibration data, Calibration Report, Pitot Calibration, Certificate of Calibration provided

Talk to an expert

Speak with one of our scientists or experts at Droplet Measurement Technologies today to discover solutions that can power your research.

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