The PWS100 determines precipitation and visibility parameters for road, marine, and airport automated weather stations. Using a novel optical system and a laser-based light source, a structured detection volume is formed. This volume allows the PWS100 to accurately determine the velocity and size of falling precipitation. The use of two separate detectors and laser Doppler anemometry techniques improve upon current present weather sensors and optical distrometers, and enables the PWS100 to accurately determine individual particle velocity and size to within ±5 percent.

Features

Uses laser doppler anemometry techniques to calculate hydrometeor size and velocity.
Identifies many precipitation types, including drizzle, rain, snow, hail, and graupel.
Determines visibility values for up to 10 km, with an accuracy of ±10%.
Calculates rain rate from volume of detected hydrometeors.
Includes a digital signal processor (DSP) that improves processing speed and accuracy.
Designed for long term, unattended operation

Specifications

Measuring Area: 40 cm2 per light sheet
IP Rating: IP 66 (NEMA 4X)
Housing Materials: Iridite NCP conversion coated aluminium (RoHS compliant) and hard anodised aluminium. Outer parts also coated with marine grade paint.

Electrical

Power Requirements
DSP Power: 9 to 24 Vdc, or 9 to 16 Vdc with CS215-PWS Temperature and RH sensor
Current Consumption: 200 mA to 1 A
Hood Heater: 24 Vac or dc, 7 A
Communication: RS-232, RS-422, or RS-485
Baud Rate: Selectable from 300 bps to 115.2 kbps
Control Unit: Custom DSP Board
EMC Compliance: Tested and conforms to BS EN61326:1998

Optical

Laser Source: Near-infrared diode, eye safe Class 1M unit output
Peak Wavelength: 830 nm
Modulation Frequency: 96 kHz
Receivers: Photodiode with band pass filters
Spectral Response: Maximum spectral sensitivity at 850 nm, 0.62 A/W (0.6 A/W at 830 nm)
Lens Check Light Source: Near-infrared LED

Measurement

Particle Size: 0.1 mm to 30 mm
Size Accuracy: ±5% for particles greater than 0.3 mm
Particle Velocity: 0 .16 m/s to 30 m/s
Velocity Accuracy: ±5% for particles >0.3 mm
Types Of Precipitation Detected: Drizzle, Rain, Snow Grains, Snow Flakes, Hail, Ice Pellets, Graupel, Mixed (combination of types above)
Rain Rate Intensity Range: 0 to 400 mm/h
Rainfall Resolution: 0.0001 mm
Rain Total Accuracy : typically ±10% (accuracy figures are for laboratory conditions with reference particles and standards; accuracy will be degraded for windy conditions, frozen precipitation, and very high rainfall rates)
Visibility Range: 0 to 20,000 m
Visibility Accuracy: ±10% to 10,000 m
Visibility measurement interval: User-selectable from 10 seconds to 2 hours
External Sensors: SDI-12 compatible sensors supported such as the CS215-PWS Temperature and RH Probe

Producing Area:USA