Richard Paul Russell Limited
MaxiMet GMX600

Gill MaxiMet GMX600 Compact Weather Station

with FREE UK Standard Delivery

£-- inc VAT
Payment Methods Accepted

We have a selection of pre-made RS232 and RS485 cables available to accompany this sensor.

The GMX600 is an extremely low maintenance, compact and durable optical rain gauge weather station measuring rainfall, wind speed and direction, temperature, relative humidity, barometric pressure, absolute humidity, air density and wet bulb temperature readings. The built-in electronic compass automatically aligns the sensor to north. Optional GPS functionality delivers true wind measurements and automatically positions the sensor.

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GMX600 Compact Weather Station Description

The Gill MaxiMet GMX600 combines the GMX100, GMX200 and GMX300 into a single unit. It is extremely compact, robust and lightweight enabling accurate measurement of wind speed, wind direction and precipitation plus a wide range of weather parameters.

Three double-louvered naturally aspirated radiation shields deliver long term highly accurate weather data. Parameters measured include temperature, relative humidity, barometric pressure, absolute humidity, air density and wet bulb temperature. In addition, an integrated optical rain gauge senses rainfall as it hits its surface, automatically measuring the raindrops' size and quantity. It then records the data from which it calculates and formats the output as if it were a traditional tipping bucket rain gauge in serial format.

In addition, a solid state ultrasonic sensor provides extremely accurate wind speed and direction measurements. An electronic compass comes as standard which delivers apparent wind, WMO wind averages and gust data.

The optional GPS adds the benefit of a true wind measurement, height above sea level, latitude, and longitude, and simplifies installation by automatically finding north.

The result is an extremely durable and cost effective maintenance free weather station widely used for applications such as agriculture, health & safety, transport, education, energy and building controls.

Richard Paul Russell Ltd. can connect the sensor to the website where data can be viewed using any internet connected device and downloaded for detailed analysis in a .CSV file format.

NOTE: The Optical Sensor provides a General Indication only of rainfall levels for use in situations where low maintenance is required. Use a tipping bucket or equivalent with a MaxiMet (e.g. GMX531, GMX550 and GMX551) where reference quality precipitation measurements are required.


• Building and industrial controls
• Authorities
• Transport
• Coastal
• Agricultural
• Safety
• Educational
• Commercial
• Energy


• Temperature, humidity and pressure sensor
    • Naturally aspirated
    • UV stable radiation shield
    • Dust and precipitation protected
• Wind sensor
    • Wind speed & direction
    • Apparent wind
    • WMO wind averages, gusts
    • Built in compass
    • GPS *Optional provides true wind, latitude, longitude and height above sea level
• Precipitation sensor
    • Optical rain gauge
    • No moving parts unlike tipping bucket rain gauges
• Lightweight and compact
• Robust construction
• Low power consumption
• No moving parts
• Extremely low maintenance
• 24 months warranty

Temp, Humidity & Pressure
Air Pressure / Temperature
Relative / Absolute humidity
Naturally aspirated UV stable radiation shield
Protection against wind-blown precipitation/dust
Rainfall total
Rainfall intensity
Rainfall Y/N
Emulated tipping bucket
Integrated heater
No moving parts
0.08 mm tip (customer select)
Wind speed & direction
Apparent and true wind (with GPS)
WMO wind averages and gust
GPS (Option)
Height above sea level m
Position of the sun
Solar Noon
MSL pressure
Temperature °C / °F / °K
Relative humidity % Rh
Barometric pressure hPa, mbar, mm Hg, In Hg
Absolute humidity g/m3
Air density kg/m3
Precipitation mm/hr, mm/total, in/hr, in/total
Wind speed m/s, hm/hr, mph, kts, ft/min
Wind direction °
True/apparent wind
Wind chill °C / °F / °K
Wet bulb temperature °C / °F / °K
Angle of Tilt
Outputs RS232, 422, 485 (ASCII), SDI-12, NMEA, MODBUS, Analogue (option)
Wind Speed
Range 0.01 m/s to 60 m/s
Accuracy ± 3% to 40 m/s,
± 5% to 60 m/s
Resolution m/s 0.01
Starting Threshold 0.01 m/s
Sampling Rate 1 Hz
Units m/s, km/hr, mph, kts, ft/min
Wind Direction
Range 0-359°
Accuracy ± 3% to 40 m/s,
± 5% to 60 m/s
Starting Threshold 0.05 m/s
Sampling Rate 1 Hz
Units Degrees
Range -40°C to +70 °C
Resolution 0.1
Accuracy ± 0.3°C @ 20°C
Sampling Rate 1 Hz
Units °C, °F, °K
Range 0-100%
Resolution 1%
Accuracy ± 2% @ 20°C (10%-90% RH)
Sampling Rate 1 Hz
Units % Rh, g/m3
Dew Point
Range -40°C to +70°C
Resolution 0.1
Accuracy ± 0.3°C @ 20°C
Units °C, °F, °K
Sampling Rate 1 Hz
Range 300 to 1100 hpa
Resolution 0.1 hPa
Accuracy ± 0.5 hPa @ 25°C
Sampling Rate 1 Hz
Units hPa, mbar, mmHg, inHg
Measurement type Optical
Range 0 to > 300 mm/hr
Precipitation Resolution 0.08 mm (Customer Selectable)
Repeatability 3%
Sampling Rate 1 Hz
Units mm/hr, mm/total, in/hr, in/total
Heating Yes
Output rate 1/s, 1/min, 1/hr
Digital Comms Modes Serial RS232, RS422, RS485, SDI-12, NMEA, MODBUS, ASCII
Analogue Outputs Available via seperate optional device
Power Supply 5 to 30 Vdc
Power (Nominal) 12 Vdc 64 mA continuous high mode 0.7 mA eco-power mode (1 hour polled)
Environmental Conditions
IP Rating 66
Operational Temperature Range -40°C to +70°C
EMC Standard BS EN 61326 : 2013
FCC CFR47 parts 15.109
CE Marking Yes
RoHS compilant Yes
Weight 0.8 Kg
Origin UK

Precipitation Care & Maintenance
Users should clean the plastic dome with a soft, lint free cloth and where necessary with a non-aggressive cleaning solution ideally once a week. Where this is not possible, cleaning should be done during regularly- scheduled visits to the sensor and site. It is recommended that the rain gauge sensor should be cleanred every 3 months as a minimum.

Users can check operation of the rain gauge by performing a simple test of functionality by spraying some water using a mist nozzle similar to that used in many households for watering plants. The MaxiMet rain gauge should register incremental rain fall when sprayed with water.

NOTE: the temperature, humidity and barometer sensors are located internally and are not maintainable or replaceable by a user. Consideration should be given to checking the pressure readings against a standard every 12 months and maintaining the temperature and humidity sensor every 12-24 months. If required you can return the MaxiMet to Richard Paul Russell Ltd to check the barometer calibration, please contact us at for more details.

Choose your sensor based on the parameters you want to measure.

GMX 200
GMX 240
GMX 300
GMX 301
GMX 400
GMX 500
GMX 501
GMX 550
GMX 551
GMX 600
  GMX200 GMX240 GMX300 GMX301 GMX400 GMX500 GMX501 GMX550 GMX551 GMX600
Wind Speed Tick Tick       Tick Tick Tick Tick Tick
Wind Direction Tick Tick       Tick Tick Tick Tick Tick
Air Temperature     Tick Tick Tick Tick Tick Tick Tick Tick
Humidity     Tick Tick Tick Tick Tick Tick Tick Tick
Pressure       Tick Tick Tick Tick Tick Tick Tick
Dew Point     Tick Tick Tick Tick Tick Tick Tick Tick
Wet Bulb Temperature     Tick Tick Tick Tick Tick Tick Tick Tick
Precipitation (Optical Rain Gauge)   Tick     Tick         Tick
Precipitation (Tipping Rain Bucket Gauge)                    
Solar Radiation       Tick     Tick   Tick  
Compass Tick         Tick Tick Tick Tick Tick
Optional GPS Positioning Tick         Tick Tick Tick Tick Tick
Side Connector for Rain Gauge               Tick Tick  

If you want to discuss a bespoke system specification or have any questions call
our technical team on +44 (0) 1590 641223 or email