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WS100 Radar Precipitation Sensor / Smart Disdrometer

Absolutely maintenance-free and extremely fast measurement of precipitation type (Rain, snow, sleet, freezing rain, hail) and intensity, thanks to radar measurement technology. The smart radar rain sensor & present weather detector!

The Lufft WS100 is our rain sensor with radar technology and adjustable heating. Using a 24-GHz Doppler radar, it measures the speed of all forms of condensed water. These include rain, freezing rain, hail, snow and sleet.
The low-energy sensor detects precipitation from the first drop. Its possible uses are nearly unlimited. Whether in hydrology and water management, agricultural and environmental science, building automation, meteorology or airport and traffic control: the rain gauge measures rain almost anywhere in the world.

  • Rain/precipitation quantity, rain/precipitation type (Rain, snow, sleet, freezing rain, hail)
  • 24GHz Doppler radar
  • Very fast response time, maintenance-free measurement, present weather detection
  • RS-485 semi-duplex two-wire, SDI-12, pulse interface / UMB protocol, Modbus
  • 8367.U03, 8367.U04, 8367.U05
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Product Advantages of the Lufft WS100 Radar Precipitation Sensor

Absolutely maintenance-free and low-energy 24-hour operation

  • Maintenance-free operation through ingenious technology without any moving parts
  • Energy-saving sensor thanks to the improved ECO mode (0.4 VA)
  • Extended heating capacity allows operation in summer as well as in winter
  • Improved heating power with lower power consumption: Sensor heating integrated directly on the dome wall, power consumption with 9 VA heating.
  • Very long service life and high operational reliability due to high quality components

Every second counts: Precise precipitation measurement from the first drop

  • Extremely fast measurement from the first raindrop
  • Detection of precipitation and rainfall (rain, freezing rain, hail, snow and sleet)
  • Detection of drop size (0.3 to 5 mm)
  • Differentiation between 11 classifications of drop sizes
  • Sensor provides rain intensity with higher resolution starting from 0.01 mm
  • Improved measurement accuracy thanks to patented self-developed radar module

Precision sensor with radar technology designed for all industrial needs

  • Precipitation sensor with radar technology: 24GHz Doppler radar
  • Designed for Weather Critical Operations and Operation Efficiency: Traffic, Rail, Renewables, Building management, Air Quality
  • Particularly suitable for places or areas which are difficult to access due to being maintenance-free
  • No maintenance or calibration, no additional hidden costs

Designed for all common data loggers and data acquisition systems

  • Multiple and simultaneous interfaces for data output and communication
  • SDI-12 and RS-485 Modbus for reliable data transmission

Examples of use of the Lufft WS100 Radar Precipitation Sensor

The maintenance-free and extremely fast measurement of precipitation type and intensity fits perfect the needs of the following applications...

Examples of Use:

  • Operation Efficiency: Traffic, Rail
  • Renewable Energy
  • Building Automation
  • Air Quality

Product variants of the Radar Precipitation Sensor WS100

Due to country-specific requirements for the radar technology of the WS100, the precipitation sensor is available in the following variants:

  • Radar Precipitation Sensor WS100 - Europe version (Article no. 8367.U03)
    Frequency range: 24,0 – 24.075 GHz, 100mW output power, CE
  • Radar precipitation sensor WS100 - USA, Canada, Brasil,… (Article no. 8367.U04)
    Frequency range:  24.075 GHz – 24.175 GHz, 100 mW output power, FCC
  • Radar Precipitation Sensor WS100 - China (Article no. 8367.U05)
    Frequency range: 24.00 – 24.25 GHz (24,0 – 24.075 GHz used), 20 mW output power, CE

Webinar: The new Lufft WS100 Radar Precipitation Sensor

Curious about innovative sensors in precipitation detection? Watch our free on demand webinar and discover the new precipitation sensor WS100, which is based on smart radar technology!

Watch the recording of the WS100 now!

EU declaration of conformity - Lufft WS100
EU declaration of conformity - Lufft WS100
Firmware - Lufft - WS100
Full User Manual - Lufft WSxxx weather sensors
Manual - Lufft - UMB ASCII 2.0 (EN)
Manual - Lufft - UMB ASCII 2.0 (EN)
Manual - Lufft UMB Config Tool (EN)
Manual - WS100
Software - Lufft - ConfigTool .NET
Version 1.6
Download as PDF
Dimensions Ø150 mm (5.9 in), height: 190 mm (7.48 in)
Suitable mast diameter 60 - 76 mm
Weight ~0.6 kg
Electrical parameters
Power supply 10...28 VDC
Power consumption without heating 1 VA / 0.4 VA (low power mode)
Heating power 9 VA
Operating parameters
Operat. temp. range -40...60 °C
Operat. humidity range 0...100 %
Protection class IP66
Survival wind speed 75 m/s
Data transfer
Interfaces/ protocols RS-485 semi-duplex two-wire, SDI-12, pulse interface / UMB protocol, Modbus
(Pluggable) cable length 10 m
Transmission frequency 24 GHz
Measurement surface 9 cm²
Precipitation types Rain, snow, sleet, freezing rain, hail, drizzle; No precipitation (SYNOP 4677)
Principle Doppler radar
Accuracy ±0.16mm or ±10% of the measured value for liquid precipitation*
*) Under laboratory conditions by means of Lufft test system: Reference drop simulator with 2.8 mm drop diameter and adjustable intensity between 10 and 200 mm/h.
Resolution liquid preciptiation 0.01 / 0 .1 / 0.2 / 0.5 / 1.0 mm (pulse interface)
Measurement ranges
Droplet size 0.3...5.0 mm
Drop Size Distribution 11 drop size classes with bandwidth of 0.5 mm
Precipitation intensity 0.01...200 mm/h / 0...7.874 inch/h
Particle velocity 0.9...15.5 m/s
Solid precipitation 5.1...~30 mm
Download as PDF

WS product family: Communication after protocol change

How to communicate with a WS-Sensor and the UMB-config-Tool if the protocol was changed for example to Modbus or SDI-12?

After a Reset ( switching On/Off the sensor) every WS-Senor will start up for the first 5 seconds in UMB-protocol and the standard baud rate of 19200Bd. Independend to the configured protocol and baudrate settings of the WS-Sensor.

In this first 5 Seconds you will be able to connect via UMB-config-Tool to the WS-Sensor after this first command was send the UMB-protocol will stay for 10 minutes after that it switches back to the original configured protocol. This Time will always be extended to 10 minutes if a new UMB command was send.

WS product family: SDI-12 wiring plan for Device version >= 42

How to connect a WS-sensor with a device version >= 42 (hardware version >=14) to a SDI-12 system?

The wiring plan has changed compared to the wiring plan of older WS-Sensor device versions.
The new wiring plan is:

  • +VDD = brown
  • GND = white
  • SDI12_Signal = yellow
  • SDI12_GND = white

This is also mentioned as a note in the latest WS-sensor manual in the section 8 Connections

WS100: How does the Doppler Radar Measurement Principle of the WS100 work?

The 24 GHz Microwave Doppler Radar works with the radar reflection method and measures the precipitation quantity or precipitation intensity by means of the correlation of drop size and velocity below the sensor.

Inside the the smart sensor a drop Size distribution matrix enables to calculate intensity of precipitation and to determine type of precipitation according fundamental meteorological relationships (Gunn-Kinzer and Hobbs and Locatelli).

More to read about the measurement principle in the WS100 Sensor Guide:

To the Download of the WS100 Sensor Guide