Description
The MaxiMet GMX301 is a specialised, WMO-compliant atmospheric sensor array that enhances the standard climate cluster with an integrated ISO 9060 Second Class pyranometer for precise solar irradiance measurement. Designed for environmental and renewable energy monitoring, it features three double-louvered, naturally aspirated radiation shields to protect the Air Temperature, Relative Humidity, and Barometric Pressure sensors from solar heating errors. Optimised for 2m-height mounting, the GMX301 requires a clear, unobstructed view of the Southern sky to accurately track Global Horizontal Irradiance (GHI) and sunshine hours. For a complete meteorological station, it can be seamlessly integrated with a GMX200 on a 10m mast for unobstructed wind monitoring and a remote Tipping Bucket Rain Gauge positioned to prevent wind-related under-catch, creating a high-integrity, modular WMO-standard infrastructure.

Temperature & Relative Humidity
- Air Temperature and Relative Humidity
- Calculated Dew Point and Absolute Humidity
- Wet Bulb Temperature (When Temperature <-20 and <50°C, 5-99%RH)
- Heat Index (When Temperature >23.88°C)
Barometric Pressure
- Barometric Pressure
- Pressure at Sea Level
- Pressure at Station
- Air Density
Solar Irradiance
- ISO Approved Solar Irradiance Readings
- Sunshine Hours (Daily Duration over 150W/m²)
Inclinometer/Compass
- Compass Reading (0-359° Magnetic North)
- X -Tilt. +ve East, -ve West
- Y -Tilt. +North, -ve South
- Z Orientation, +1 Normal Upright, -1 Inverted Position
- X & Y Can Provide 2 Decimal Points for Easy Installation.
Additional Parameters
- Twilight. (Civil, Nautical and Astronomical)
- Time of Sunrise, Solar Noon, Sunset (Location Required)
- Position of the Sun
- Supply Voltage
- System Status
- System Time and Date
- Custom User Information (up to 16 character).
Parameter Specifications
| Parameter | Range | Resolution | Accuracy | Units of Measure |
| Compass | 0-360° | 1° | ±3° | Degrees |
| Temperature | -40 to +70°C | 0.1°C | ±0.3°C | °C, F or °K |
| Humidity | 0-100%RH | 1%RH | Typically ±2%RH | %RH, g/m² |
| Dew Point | -40 to +70°C | 0.1°C | °C, F or °K | |
| Pressure | 300-1,250hPa | 0.1hPa | ±0.4hPa (Absolute) ±0.8hPa (Relative) |
hPa, mBar, mmHg, InHg |
| Solar Irradiance | 0-1,600W/m² | 1W/m² | W/m² |
GMX301 Specifications
| Output Rate: | 1Hz, 1 reading per minute, 1 Reading per hour, or Polled Mode |
| Digital Comms: | RS232, RS485, RS422, SDI-12, NMEA, Modbus, ASCII |
| Power Supply: | 5-30vDC |
| Consumption @ 12vDC: | 5.5mA |
| IP Rating: | IP66 |
| Operational Temperature Range: | -35 to +70°C |
| CE Marking: | Yes |
| Dimensions: | 198 x 142 x 142mm |
| Weight: | 0.6Kg |
| Origin: | UK |
| Warranty: | 24 Months |
