PWS100
Overview
The PWS100 is a laser-based sensor that measures precipitation and visibility by accurately determining the size and velocity of water droplets in the air. It can be used in weather stations in road and airport applications. The PWS100 uses advanced measurement techniques and algorithms to calculate individual precipitation particle type.
For aviation appplications, users can be assured that the PWS100 complies with CAA and ICAO guidance and meets or exceeds all recommendations and specifications. (This includes CAP437, CAP670, and CAP746.) ICAO compliant frangible masts are available for aviation use.
To enhance the PWS100 algorithms, Campbell Scientific recommends adding a CS215-PWS Temperature and Relative Humidity Probe (listed on the Ordering Information page under Common Accessories), which will cause the data from the CS215-PWS to be fed directly into the PWS100 precipitation type and visibility algorithms.
Note: Campbell Scientific does not recommend using the PWS100 for marine applications.
Key Advantages
Identifies size, type, and velocity of precipitation
Technical Description
The PWS100 Present Weather Sensor is a laser-based sensor capable of determining precipitation and visibility parameters for automatic weather stations including road and airport stations. Due to its advanced measurement technique and fuzzy logic algorithms, the PWS100 can determine individual precipitation particle types from accurate size and velocity measurements and the structure of the received signal. Auxiliary measurements of temperature and relative humidity (RH) provide improved particle classification.
The PWS100 consists of a Digital Signal Processor (DSP) housing unit connected to a sensor arm that contains one laser head and two sensor heads. Each sensor head is 20° off axis to the laser unit axis—one in the horizontal plane and the other in the vertical plane. The PWS100 ships with a stainless-steel quick-release clip-on V-bolt mounting bracket that attaches the DSP housing to a mast or pole.
Benefits
- Unique calibration kit available to calibrate particle size and speed measurement to give confidence in reliable measurement of present weather parameters
- Identifies many precipitation types, including drizzle, rain, snow, hail, and graupel
- Patented four beam, two receiver system directly measures hydrometeor size and velocity
- Reports MOR Visibility in range 0 to 20,000 m with programmable alarm
Specifications
- Measuring Area
- 40 cm2 per light sheet
- IP Rating
- IP 66
(NEMA 4X)
- Housing Material
- Iridite NCP conversion coated aluminium (RoHS compliant) and hard anodized aluminum
- 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
- Dimensions
- 115 x 70 x 40 cm
(45.28 x 27.56 x 15.75 in.)
- Weight
- 8 kg
(17.6 lb)
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
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 to 30 mm
(0.0039 to 1.18 in.)
- Size Accuracy
- ±5%
(for particles greater than 0.3 mm [0.0118 in.])
- Particle Velocity
- 0.16 to 30 m/s
- Velocity Accuracy
- ±5%
(for particles > 0.3 mm [0.012 in.])
- Types of Precipitation Detected
- Drizzle, rain, snow grains, snowflakes, hail, ice pellets, graupel, mixed (combination of types above)
- Rain Rate Intensity Range
- 0 to 999.9 mm/h-1
- 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
(0 to 65,616.8 ft)
- Visibility Accuracy
- ±10% to 10,000 m
(±10% to 32,808.4 ft)
- Visibility Measurement Interval
- User-selectable from 10 s to 2 h
- External Sensors
- SDI-12 compatible sensors supported
(such as the CS215-PWS Temperature and RH Probe)
- Detection Threshold
- > 0.02 mm hr-1
- Accumulation Accuracy
- ±10%
Common Accessories
(9)41303-5A
6-Plate Solar Radiation Shield
The 41303-5A provides a 6-plate naturally-aspirated radiation shield that houses one CS215-PWS probe. Its louvered construction allows air to pass freely through the shield thereby keeping the probe at or near ambient temperature. The 41303-5A attaches to a crossarm, mast, or user-supplied pipe with a 1.0" to 2.1" OD.
OrderableRAD06
6-Plate Solar Radiation Shield
The RAD06 uses a double-louvered design that offers improved sensor protection from driving rain, snow, and insect intrusion. It also has lower self-heating in bright sunlight combined with higher temperatures (> 24°C (~75°F)) and low wind speeds (< 2m/s (~4.5 mph)), providing a better measurement.
Orderable25295
24/12 Vdc Power Supply for PWS100
The 25295 supplies 24 Vdc and 12 Vdc power; the hood heater requires 24 Vdc. The 25295 consists of a 24 Vdc, 10 A DIN-rail-mounted power supply and a 10 A, 12 V regulator (CH200), housed in an environmental enclosure. Access to ac power is required. The customer needs to order a battery (see below).
OrderableBP7
7 Ah 12 V Sealed Rechargeable Battery
Three battery choices are offered for the 25295 Power Supply. The BP7 is a 7 A h, 12 Vdc sealed rechargeable battery. This battery includes the #17364 cable, the #10508 enclosure mounting bracket, four screws, and four grommets. The 17364 cable terminates in pigtails that attach to the 25295's MorningStar regulator.
OrderableBP12
12 Ah 12 V Sealed Rechargeable Battery with Mounts
Three battery choices are offered for the 25295 Power Supply. The BP12 is a 12 A h, 12 Vdc sealed rechargeable battery. This battery includes lead wires and hardware for mounting it to an enclosure backplate. The connector provided on the lead wires needs to be cut off to use with the 25295.
OrderableBP24
24 Ah 12 V Sealed Rechargeable Battery
Three battery choices are offered for the 25295 Power Supply. The BP24 is a 24 A h, 12 Vdc sealed rechargeable battery. This battery includes lead wires and hardware for mounting it to an enclosure backplate. The connector provided on the lead wires needs to be cut off to use with the 25295.
OrderableCS140
Background Luminance Sensor
The CS140 is a high-quality background luminance sensor. It provides the luminance data required to assess the visibility range for lights such as runway lights or warning lights.
Orderable34296
CS140 Maintenance Cable
The 34296 cable, used with the CS140 Background Luminance Sensor, forces communications to RS-232 38400 baud, and sensor id “0.” The CS140 continues to draw power from the existing power source. After the sensor is removed from its power source, the sensor returns to its previous communication address and settings.
Orderable34295
CS140 Calibrator
The CS140 Calibrator is a high-quality device to generate a known luminance level for calibrating a CS140 Background Luminance Sensor. It is powered from the CS140 supply and is used while in communication with it.
Orderable
Compatibility
Compatible Products
(2)
Related Resources
Case Studies
Documents
Downloads
- Software ApplicationsPWS100 Present Weather Viewing Softwarev2.6.1
January 24, 2012
Designed to complement the PWS100 the Present Weather Viewer provides a simple yet comprehensive interface showcasing many of the capabilities of the PWS100 whilst providing easy configuration of key sensor features.
- OS and FirmwarePWS100 OSv7
November 30, 2015
Current PWS100 operating system.