How does the GMX500 measure wind without moving parts?

Omni Instruments Expert Response: It uses ultrasonic pulses sent between three transducers. By measuring the time it takes for the pulses to travel between the sensors, the unit calculates precise wind speed and direction with zero mechanical wear.

What is the benefit of the GPS option on the GMX500?

Omni Instruments Expert Response: The GPS module allows the station to output "True Wind" by compensating for the movement and orientation of the station itself. It also provides precise GPS location and a high-accuracy real-time clock for data logging.

Does the unit require annual calibration?

Omni Instruments Expert Response: Because there are no moving parts to wear out, the ultrasonic wind sensors do not drift like mechanical cups. However, we recommend a 2-year verification check of the temperature and humidity cluster to maintain WMO accuracy standards.

Can I connect the GMX500 directly to a PLC?

Omni Instruments Expert Response: Yes. The GMX500 natively supports Modbus RTU (RS485), which is the industry standard for PLCs and SCADA systems.

Is the heating element always on?

Omni Instruments Expert Response: No. The heating variant uses an internal thermostat to activate only when temperatures drop and moisture is detected, ensuring efficient power management in solar-powered installations.

GMX500 Weather Station for Wind, Temp, RH & Pressure

The MaxiMet GMX500 is a combined instrument mounted inside three double louvered, naturally aspirated radiation shields for the measurement of wind speed and direction, ambient temperature, humidity and pressure, with no moving parts. The results are high performance across each measurement over long periods of time. The data is output in serial formats – RS232, RS485. SDI12, NMEA and MODBUS.

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Description

Description

The MaxiMet GMX500 is a professional-grade, solid-state weather station designed to provide a comprehensive meteorological profile without moving parts. By integrating ultrasonic wind speed and direction sensors with high-accuracy climate clusters for Temperature, Relative Humidity, and Barometric Pressure, it offers a maintenance-free alternative to traditional mechanical stations. The unit features triple double-louvered radiation shields to eliminate solar heating errors and can be configured with an optional internal GPS and Heating module for operation in extreme environments or on moving assets. Engineered for seamless integration, the GMX500 provides WMO-compliant data strings via RS232, RS485, Modbus, and NMEA, making it the primary choice for industrial automation, smart city infrastructure, and remote environmental monitoring.

Wind

Relative Wind Speed & Direction. Relative to the North Marker
Average Wind Speed & Direction. Short and Long Term Averages
Corrected Wind. Corrected to Magnetic North
True Wind & Direction. Corrected by GPS (Option).
Gust Speed & Direction (WMO)
Corrected Gust Speed & Direction (WMO) (Requires GPS)

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)
Wind Chill (When Temperature <10°C and wind speed >1.5m/s

Barometric Pressure

Barometric Pressure
Pressure at Sea Level
Pressure at Station
Air Density

GPS (Option)

GPS Location (Longitude, Latitude)
GPS Height
Real Time Clock
GPS Heading
GPS Speed
GPS Status

Inclinometer/Compass

Compass Reading (0-359° Magnetic North)
X -Tilt. +ve East, -ve West
Y -Tilt. +ve 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 (RTC with GPS Option)
Custom User Information (up to 16 character).

Parameter Specifications

Parameter	Range	Resolution	Accuracy	Units of Measure
Wind Speed	0-60m/s	0.01m/s	0.3ms (0-10m/s) 3% (10-40m/s) 5% (40/60m/s)	m/s, Km/h, mph, kts, ft/min
Wind Direction	0-360°	1°	±3° (0.5-40m/s) ±5° (40-60m/s)	Degrees
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

GMX500 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 (10-35vDC with Heating)
Consumption @ 12vDC:	24mA (GPS +10mA, Heating +400mA)
IP Rating:	IP66
Operational Temperature Range:	-35 to +70°C (-40 to +70°C with Heating)
CE Marking:	Yes
Dimensions:	222 x 142 x 142mm
Weight:	0.7Kg
Origin:	UK
Warranty:	24 Months

Product

Ref

Price

Product Description

1957-0500-60-000

£1,614.00

MaxiMet GMX500 Compact Weather Station. Measured Parameters: Relative Wind Speed, Wind Direction, Air Temperature, Relative Humidity, Barometric Pressure, 2-Axis Compass Heading. Derived Parameters: Average Wind Speed & Direction, Corrected Direction, Gust Speed & Direction, Dew Point, Wet Bulb Temperature, Wind Chill, Heat Index, Absolute Humidity, Air Density and Pressure at Sea Level. Outputs: RS232, 422, 485 (ASCII), SDI-12, NMEA, Modbus. Power Supply: 5-30vDC (Consumption 24mA @ 12vDC).

1957-0500-60-100

£1,815.00

MaxiMet GMX500 Compact Weather Station with GPS. Measured Parameters: Relative Wind Speed, Wind Direction, Air Temperature, Relative Humidity, Barometric Pressure, 2-Axis Compass Heading, GPS Location, Heading and Speed. Derived Parameters: Average Wind Speed & Direction, Corrected Direction, Gust Speed & Direction, True Wind Speed and Direction correcting for misalignment or motion, Height above Sea Level, Dew Point, Wet Bulb Temperature, Wind Chill, Heat Index, Absolute Humidity, Air Density and Pressure at Sea Level. Outputs: RS232, 422, 485 (ASCII), SDI-12, NMEA, Modbus. Power Supply: 5-30vDC (Consumption 34mA @ 12vDC).

1957-0500-60-001

£1,798.00

MaxiMet GMX500 Compact Weather Station with Heating. Measured Parameters: Relative Wind Speed, Wind Direction, Air Temperature, Relative Humidity, Barometric Pressure and 2-Axis Compass Heading. Derived Parameters: Average Wind Speed & Direction, Corrected Direction, Gust Speed & Direction, Dew Point, Wet Bulb Temperature, Wind Chill, Heat Index, Absolute Humidity, Air Density and Pressure at Sea Level. Outputs: RS232, 422, 485 (ASCII), SDI-12, NMEA, Modbus. Power Supply: 10-30vDC (Consumption 424mA @ 12vDC).

1957-0500-60-101

£1,999.00

MaxiMet GMX500 Compact Weather Station with GPS and Heating. Measured Parameters: Relative Wind Speed, Wind Direction, Air Temperature, Relative Humidity, Barometric Pressure, 2-Axis Compass Heading, GPS Location, Heading and Speed. Derived Parameters: Average Wind Speed & Direction, Corrected Direction, Gust Speed & Direction, True Wind Speed and Direction correcting for misalignment or motion, Height above Sea Level, Dew Point, Wet Bulb Temperature, Wind Chill, Heat Index, Absolute Humidity, Air Density and Pressure at Sea Level. Outputs: RS232, 422, 485 (ASCII), SDI-12, NMEA, Modbus. Power Supply: 10-30vDC (Consumption 434mA @ 12vDC).

1957-10-065

£130.00

MaxiMet 1.8 Metre RS232 to USB converter including 5vDC power and communication configuration cable (9 way MaxiMet connector fitted one end and USB connector at the other end). Simplifies the connection of the MaxiMet units to a PC

1771-PK-115

£286.00

Anodized Aluminium Bracket for mounting to pole and wall. Includes an aluminium sensor adaptor for WindSonic or MaxiMet, fully anodised to reduce corrosion. The Bracket uses a mounting clamp suitable for attaching to a vertical pipe with a diameter of 30-58mm. When mounting the MaxiMet, consider the position, orientation and alignment of the unit. Mount at the top of a pipe to ensure a clear unobstructed measurement view. Kit includes stainless steel mounting bolts, multiple earth points and wall / pole mounting kit

M-TPB

£155.82

Weather station tripod mounting kit with 2m pole. The legs on this tripod are not adjustable for uneven surfaces and ground should be levelled prior to installation. ¼” stake kit (M-SKB), ½” Stake kit (M-SKA), Guy wire kit (M-GWA) and Grounding kit (M-GKA) are available separately.

M-GWA

£114.16

M-GWA Guy Wire Kit for the M-TPA or M-TPB tripods. Can be secured to Stakes spaced around the 2m tripod at a distance of 3 or 4 m, or to the tripod legs of the 3m tripod. This helps secure the tripod in place and reduces any movement due to wind.

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GMX500 Weather Station for Wind, Temp, RH & Pressure

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GMX500 Weather Station

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