Lufft WS400 Compact Weather Sensor

Lufft WS400Compact Weather Sensor

The WS400 accurately measures:
  • Air temperature
  • Relative humidity
  • Air pressure
  • Precipitation
  • Serial Output – RS485 Modbus or SDI-12
  • Low power consumption
  • Integrated heater
  • Aspirated radiation shield
  • Optional remote temperature probe


Lufft WS400 all-in-one compact weather station

The Lufft WS400 is ideal for measuring air temperature, relative humidity, solar irradiance, and air pressure. It is suitable for high-end applications where accuracy and build quality cannot be compromised.

The sensors are protected by a radiation shell for protection and to ensure measurement accuracy, making the WS400 compliant according to WMO guidelines.

The WS400 is suitable for all climates, with a temperature range of -50 to +60 °C. There are no moving parts and data processing is built-in. This makes the WS400 incredibly robust and easy to use.

As standard, we supply the Lufft WS400 with Modbus communications. However, it is possible to supply the sensor with SDI-12. Please let us know at the time of ordering which you would prefer.

As with all WS series compact weather sensors, it is possible to fit a temperature probe. The probe measures surface temperature and is ideal for the PV solar sector to measure the back of panel temperature.

Dimensions Ø ca. 150 mm, height ca. 280 mm
Weight Approx. 1.3 kg
Interface RS485, 2 – wire, half – duplex
Power supply 11 to  32 VDC
Power supply 5 to 11 VDC (electronics with limited precision of measurements)
Power supply 24 VDC +/- 10% (heater)
Power consumption 20 VA (heater)
Operating temperature -50 to 60 °C (with heater)
Operating rel. humidity 0 to 100 % RH
Cable length 10 m
Protection level housing IP66
Mast mounting suitable for Mast diameter 60 – 76 mm
Principle  NTC
Measuring range  -50 to 60 °C
Unit °C
Accuracy ±0.2 °C (-20…50 °C), otherwise ±0.5 °C (>-30 °C)
Relative humidity
Principle Capacitive
Measuring range  0 to  100 % RH
Unit % RH
Accuracy  ±2 % RH
Air pressure
Principle MEMS capacitive
Measuring range  300 to 1200 hPa
Unit hPa
Accuracy ±0.5 hPa (0 to 40 °C)
Droplet size 0,3 … 5 mm
Detection sensitivity 0,01 mm/h
Particle velocity 0.9 … 15.5 m/s
Precipitation types rain/ snow
Solid precipitation 5.1 … ~30 mm
Intensity range 0…200mm/h
Intensity resolution 0.01 mm/h
Amount resolution 0.1 mm
Accuracy 20 % under laboratory conditions
Reproducibility Typical >90 % under laboratory conditions

WS Series Frequently asked questions.

How do I mount my WS sensors? 

The sensor can be mounted directly onto a 60mm diameter pole. The sensors come with ‘U’ mounting brackets. A mounting arm (which can attach to 40-80mm diameter poles) can be supplied too.

Are other communications protocols possible?

Possible interfaces are RS485 with supported protocols UMB-Binary, UMB-ASCII, Modbus-RTU, Modbus-ASCII, XDR, and SDI-12.

What data logger is the WS400 compatible with?

The WS400 is compatible with many commercially available Met/HydroMet dataloggers and PLS systems thanks to an open communication protocol.

Optional Extras:
  • External temperature probe (can be used as a back of module temperature sensor)
  • Rain gauge Lufft WTB100