
The limit belongs at the site,
not at the nearest airfield
Heated ultrasonic wind measurement and compact stations for landing sites, including improvised ones chosen minutes earlier, so the crew makes the call on conditions where they are landing.
The nearest airfield is describing somewhere else
A landing site is frequently chosen minutes before it is used, at night, next to buildings or trees that are doing things to the wind that no forecast accounts for.
The conditions the crew are given usually come from the nearest airfield, which may be many miles away and sited in open ground precisely so that its measurement is undisturbed. That is the opposite of the information needed.
Turbulence is the part that matters most and is measured least. A mean wind speed inside limits can accompany a rotor off a treeline or a building that makes the approach unacceptable, and nothing in the reported figure shows it.
Every public decision starts at a measurement point
Three views of the work public bodies do with measurement: observe and forecast, manage and regulate, warn and respond. From rainfall and rivers to bridges, flood infrastructure and the incident itself.
Observing station wind
A national network reports wind at the same height, the same way, for decades, and every change of instrument is a potential step in the record.
- WindObserver 75 heated, 316 stainless, IP66, no moving parts
- MetConnect One separable sensors, each sited at its own height
- WindSonic 75 0 to 75 m/s, 0.5 kg, low mast loading
Temperature, humidity and pressure
Air temperature, humidity and pressure underpin every forecast, frost warning and climate statistic, and they have to be measured at screen height, clear of the mast.
- MetConnect THP temperature 0.2 degrees C, humidity 1.5 percent RH, pressure accuracy 0.5 hPa
- MetConnect One Pt100 to IEC 60751 input for a reference thermometer
- MaxiMet GMX300 temperature, humidity and pressure, no wind
Rainfall intensity
Rainfall is the input to the flood model, the drought statistic and the drainage design, so a gauge that can block with debris puts the record at risk when it matters most.
- TruMet PW100 optical, 0 to 200 mm/hr, one pulse per 0.1 mm into an existing logger
- MetConnect One contact closure input for rainfall alongside the weather
- MaxiMet GMX603 integrated optical rainfall alongside the weather
Calibration and evidence
A regulator, an inquiry or a court can ask what was measured, when and how it was verified. That is a calibration question years before it is asked.
- UKAS-accredited air velocity calibration traceable certification for anemometers
- Multi-parameter calibration six parameters, equipment from any manufacturer
- Recalibration scheduling intervals, reminders and turnaround
Agricultural field stations
Frost, spraying and irrigation decisions are made field by field, on conditions that can differ sharply from the nearest regional station.
- MaxiMet GMX551 wind, T, H, P, solar and rainfall in one housing
- MaxiMet GMX501 adds solar radiation to wind, T, H and P
- MetConnect One analogue and Pt100 inputs for third-party instruments
Remote power and resilience
Most public monitoring sites have no mains, so solar, battery and a power budget decide what can be installed and whether it keeps reporting.
- MetConnect THP 5 to 30 V DC, less than 70 mA at 12 V DC
- MaxiMet GMX200 0.5 kg, single supply, minimal draw
- MaxiMet GMX301 solar radiation for a PV-powered site
Gauging station and telemetry
A gauging station is judged on the events it captured, not the years it sat quietly, and it has to report from somewhere with no mains and no visitor.
- MetConnect One SDI-12 v1.3 into an existing hydrometric logger
- MetConnect THP 5 to 30 V DC, under 70 mA at 12 V DC
- MaxiMet GMX400 temperature, humidity, pressure and rainfall
River level and flood warning
Flood warning lead time is the whole product, and it comes from level measurement that was already installed and already working.
- LevelPro capacitive level, no moving parts to silt up
- LevelSlick FEP coated for silty and debris-laden water
- TruMet PW100 rainfall intensity to 0 to 200 mm/hr alongside level
Coastal surge and tidal flooding
Surge combines tide, pressure and wind, so a coastal warning needs all three measured locally rather than two of them inferred.
- WindObserver 75 316 stainless, IP66, Lloyd’s Register Type Approved
- MetConnect THP pressure 300 to 1100 hPa, accuracy 0.5 hPa
- LevelPro water level with no moving parts in salt water
Bridge and exposed road wind
Bridge closures, speed restrictions and high-sided vehicle bans are set on wind measured at the structure, and the decision is questioned the moment traffic stops.
- WindObserver 75 heated, 316 stainless, IP66, no moving parts
- WindObserver 90 0 to 90 m/s for exposed estuary crossings
- WindUltra compact 2-axis, IP69k, for deck-level positions
Air quality and pollution monitoring
A pollution reading only tells a regulator where it came from when wind speed and direction are measured at the same site and the same time.
- WindSonic 60 0 to 60 m/s, economical across a network of sites
- MaxiMet GMX500 wind, temperature, humidity and pressure in one unit
- WindMaster Pro 3-axis to 32 Hz where dispersion and stability matter
Cold weather and winter planning
Gritting, warm spaces and cold weather alerts are all triggered on measured temperature, and they are all funded on the assumption the trigger is right.
- MetConnect THP Pt100 input for a surface temperature probe
- MaxiMet GMX400 temperature, humidity, pressure and rainfall
- WindSonic M heated, operating to -40 degrees C
Civic buildings and public estate
Public buildings become rest centres and reception centres, and their heating, ventilation and drainage are all somebody in an office deciding without data.
- MetConnect THP temperature 0.2 degrees C, humidity 1.5 percent RH
- MaxiMet GMX551 rooftop station with wind, T, H, P, solar and rainfall
- MaxiMet GMX300 temperature, humidity and pressure only
Heat alerts and public health
Heat health alerts and worker safety both rest on the same measurement, and a shaded enclosure reading is not what people are exposed to.
- MaxiMet GMX552 WBGT heat stress with wind, T, H and P, 1.29 kg, IP66
- MaxiMet GMX551 wind, T, H, P, solar and rainfall in one housing
- MetConnect THP reference temperature and humidity
Flood barriers and defences
A demountable defence has to be deployed before the peak, which means the decision is made on a measurement rather than on a look at the river.
- LevelPro continuous level upstream of the defence
- Blade position sensors non-contact position proving on gates and penstocks
- TruMet PW100 catchment rainfall intensity, no bucket to block
Sluice, gate and penstock position
A gate that is commanded shut has to prove it is shut, under water and in silt, with a sensor that does not wear every time it moves.
- Blade360 full 360 degree contactless position, IP67, sealed for temporary immersion (1 m for 30 min)
- Blade60 contactless linear position to 60 mm
- Blade Dual Output a second channel where redundancy is required
Flood pumping station machinery
A flood pump runs hard for a few days a year and sits idle in between, so gearbox and engine wear has to be caught before the event, not during it.
- WearDetect fine and coarse ferrous debris, water presence and oil temperature
- WearDetect with Display the same sensor with an integrated display
- Outputs 0-10 V, 4-20 mA, CANbus or Modbus RTU into telemetry
Wet well and sump level
Pump start and stop, overflow alarms and spill reporting all hang on the level in a wet well full of debris and rag.
- LevelSlick coated for dirty, viscous and conductive liquids
- LevelPro stainless steel, IP66 and IP68, 0-10 V or 4-20 mA, RS232 for configuration
- DD1615 level display where a local readout is needed
Mobile incident command
A command vehicle arrives with its own met capability because the nearest station is somewhere else and the incident is here.
- MaxiMet GMX551 wind, T, H, P, solar and rainfall on one mast
- MaxiMet GMX200 wind only, 0.5 kg, fastest to raise
- WindUltra compact 2-axis, IP69k, low power for vehicle mounting
Deployable met mast
A mast that takes twenty minutes to set up in weather is a mast that does not get set up.
- MaxiMet GMX200 one unit, one cable, one output string
- MetConnect One SDI-12, Modbus and NMEA 0183 into a logger
- WindSonic 60 0.5 kg, configured with the free MetSet software
Air ambulance and landing sites
A landing site is chosen in minutes and used at night, and the wind limit is checked where the aircraft is going rather than where the met station is.
- WindObserver 70 heated, IP66, 316 stainless, marine type approved
- MaxiMet GMX501 compact station for a hospital or fixed landing site
- WindSonic M heated, 0.9 kg, for a temporary pad-side reference
Fire ground and smoke plume
Where the smoke goes decides who is evacuated, and that is a wind direction question answered at the incident within the first few minutes.
- MaxiMet GMX200 wind only, 0.5 kg, raised in a minute
- WindMaster Pro 3-axis to 32 Hz where plume rise matters
- MaxiMet GMX500 wind, temperature, humidity and pressure
Hazardous release and dispersion
Plume modelling for a chemical release is only as good as the wind and stability data going into it, and the model is being run while people wait.
- WindMaster Pro 3-axis to 32 Hz for stability and dispersion
- MetConnect THP two analogue inputs for detection equipment
- WindObserver 75 a fixed reference at a COMAH or similar site
Water rescue and boat operations
Crews on the water need wind and conditions from the boat, on a platform where everything gets wet and nothing gets serviced mid-operation.
- WindUltra compact 2-axis, IP69k, built for wet mobile platforms
- MaxiMet GMX260 marine model with a 6-axis compass, IP66 and IP68
- MaxiMet GMX200 wind only, 0.5 kg, for a shore reference
Temporary events and crowd safety
Temporary structures, stages and marquees carry wind limits, and the decision to strike them is made by somebody who will be asked to justify it.
- WindSonic 75 0 to 75 m/s, 0.5 kg, for a temporary mast
- MaxiMet GMX200 wind only, quick to raise and configure
- WindObserver 90 0 to 90 m/s for an exposed site
Wind at the pad, and what the surroundings are doing to it
Wind speed and direction at the landing point are different from wind at a reference station, and the difference grows with everything built or grown nearby. That is true at a hospital pad and more so at an improvised site.
Turbulence is generated by the same surroundings. Buildings, treelines and terrain shed structure into the flow, and a three-axis measurement is what makes that visible rather than averaged into a mean.
For established sites the measurement can be permanent, which means it has to survive years of weather with no attention, in a location that is by definition awkward to reach with a ladder.
For improvised sites it has to arrive with the crew or the vehicle, work immediately and need nothing. Those are different specifications for the same decision.
Measured where the aircraft lands
A pad-side measurement gives the crew a reference at the point of landing rather than one taken from a main met station some distance away, which is the difference between information and context.
MaxiMet brings wind, temperature, humidity, pressure, solar radiation and rainfall into one unit on one cable, and GMX200 provides wind only at 0.5 kg where that is the decision being supported.
The reading from the landing point
View MaxiMetHeated, and honest about failing
A permanent pad sensor is on a mast or a building edge and will not be visited. The failure mode that matters is not one that stops, it is one that ices, seizes and keeps reporting a calm that is inside every limit.
Ultrasonic measurement has no rotating sensing element to ice or seize. WindSonic M is heated aluminium operating to -40 degrees C, and WindObserver is heated 316 stainless at IP66, icing tested to MIL-STD-810F.
No rotating element to seize
Explore wind sensorsAviation decisions are reviewed
Operational decisions about whether a landing was acceptable are reviewed, and occasionally investigated. The conditions at the site at the time are central, and a measurement from the site is a different answer from a retrieved forecast.
Traceable calibration keeps that usable. Instruments on an interval support the decision that was taken rather than requiring it to be justified from inference.
Labcal is an independent UKAS-accredited laboratory operating to ISO/IEC 17025:2017, calibrating equipment from any manufacturer, which suits an estate of pads instrumented at different times.
What a landing site measures
Wind and turbulence at the landing point, heated for the winters a permanent pad has to work through, and compact enough for a site chosen minutes earlier.
Established pads

WindObserver
Heated 316 stainless open-head 2-axis anemometer
Heated 316 stainless measuring to 0 to 90 m/s, for a mast or building edge that will not be revisited.

MaxiMet
All-in-one weather station, no moving parts
Wind, temperature, humidity, pressure, solar radiation and rainfall from one unit at the pad itself.

WindMaster
3-axis ultrasonic anemometer
Three-axis measurement where buildings or terrain make turbulence rather than mean wind the limiting factor.
Improvised and mobile

WindSonic
Lightweight 2-axis ultrasonic anemometer
Lightweight ultrasonic measurement for a mast one person can raise, heated to -40 degrees C on WindSonic M.

WindUltra
Compact 2-axis ultrasonic anemometer
A compact 2-axis anemometer for vehicle mounting, sealed to IP69k and deployed by arriving.

TruMet PW100
Infrared optical rain gauge
Optical rainfall measurement with nothing to block, where the site record needs precipitation.
Where landing site measurement does the work
Permanent pads
Wind and turbulence at the pad, on a rooftop or building edge that nobody can reach easily.
Improvised sites
Measurement that arrives with the vehicle at a site chosen minutes earlier.
Night operations
Conditions at the landing point where the crew is making the call in the dark.
Urban landings
Sites surrounded by buildings that generate turbulence a forecast cannot describe.
Exposed decks
Heated measurement for positions where icing and exposure are routine.
Multiple pads
A consistent measurement standard across pads instrumented at different times.
UKAS-accredited calibration for six measurement parameters
Labcal is an independent UKAS-accredited calibration laboratory, Lab 0625, operating to ISO/IEC 17025:2017. It provides calibration across gas and air flow, air velocity, liquid flow, pressure, temperature and humidity.
For a pad estate carrying anemometers, thermal probes, pressure instruments, thermometers, temperature and humidity probes and data loggers, one accredited laboratory keeps sites instrumented at different times on a single traceable schedule.
Gas meters · Mass flow controllers · Dispensing systems
Anemometers · Pitot tubes · Thermal probes
Flow meters and sensors · Process control equipment
Gauges · Transducers · Manometers · Transmitters
Thermometers · Probes · Thermocouples · Data loggers
Hygrometers · Probes · Transmitters
Getting conditions to the crew
A landing decision is taken by a crew who may be airborne, so the measurement has to reach a display, a dispatch system or a radio call rather than an archive.
Gill supports environmental monitoring, industrial sensing, embedded electronics and systems integration, so operators, hospital estates and vehicle builders can bring measurement into operational systems.
Whether the requirement is a serial string into a dispatch or display system, CAN into a vehicle network, Modbus into a building system, or analogue into an existing channel, Gill engineers can support integration from specification through commissioning.
Outputs and options
- RS232 & RS485 : Dispatch systems and pad displays
- CAN : Vehicle networks
- Modbus RTU : Building and estate systems
- Traceable calibration : So the decision holds up on review
What the specification looks like in practice
Measured at the landing point
Wind at a pad differs from wind at a reference station, and the difference grows with everything built or grown nearby.
Turbulence made visible
Three-axis measurement resolves the structure that buildings and treelines shed, which a mean wind speed hides.
Nothing rotates, so nothing seizes
The failure that matters is an iced anemometer reporting calm, and ultrasonic measurement removes it.
Heated for the winter
WindSonic M operates to -40 degrees C, and WindObserver is heated 316 stainless, icing tested to MIL-STD-810F.
Light enough for an improvised site
GMX200 measures wind at 0.5 kg, and WindUltra mounts on a vehicle.
Defensible if it is reviewed
Independent UKAS-accredited calibration across six parameters, for equipment from any manufacturer.
Questions about air ambulance and landing sites
Because an airfield is sited in open ground specifically so its measurement is undisturbed, which is the opposite of a landing site surrounded by buildings or trees.
The difference is largest exactly where it matters, which is at an improvised or urban site.
WindMaster provides three-axis measurement at 20 Hz with options up to 32 Hz, which resolves the structure buildings and terrain generate rather than averaging it into a mean.
Something that arrives and works. GMX200 measures wind at 0.5 kg for a mast one person can raise, and WindUltra is a compact anemometer for vehicle mounting, sealed to IP69k.
Ultrasonic sensors have no rotating element to ice, foul or seize. WindObserver is heated 316 stainless at IP66, icing tested to MIL-STD-810F, for positions that will not be revisited.
Generally yes. The sensors provide serial, CAN, Modbus and analogue outputs, and the engineering team can advise on the interface a particular dispatch or display system expects.
Yes. Labcal is an independent UKAS-accredited calibration laboratory, Lab 0625, operating to ISO/IEC 17025:2017, calibrating equipment from any manufacturer across gas and air flow, air velocity, liquid flow, pressure, temperature and humidity.
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