Certification decides the shortlist
before performance is discussed
Intrinsically safe wind measurement and capacitive liquid level sensing for fuel storage, hydrant systems and refuelling areas, where the classification comes first and the measurement still has to work.
A classified area removes most of the options
Fuel storage, hydrant systems and refuelling areas are classified hazardous areas, and that classification sets the equipment before anyone discusses accuracy, output or price. An instrument without the right certification is not a compromise, it is not on the list.
What follows is that the shortlist is short, and it is easy to end up specifying whatever is certified rather than what the application actually needs. That trade shows up later as a measurement that is compliant and not very useful.
The measurements themselves have not gone away. Wind direction decides the response to a spill or a vapour release, and tank level is a stock figure, a delivery decision and a safety limit at the same time.
Every airfield decision starts at a measurement point
An airport measures across the whole estate. Surface wind along the runway. Temperature, humidity and precipitation for approach and de-icing. Heat stress and machinery condition on the apron.
Runway threshold and touchdown zone
Surface wind at the threshold is the number the crew acts on, and it is reported continuously whether or not anyone can reach the mast.
- WindObserver 70 FAA and CAA accepted for AWOS use, heated head, 0 to 70 m/s
- WindObserver 75 316 stainless open head where site winds run higher
- WindSonic 60 lighter 2-axis for a secondary reference
Runway midpoint reporting
Wind can differ along the length of a runway, so mid-point sensors give the tower a truer picture than a single threshold reading.
- WindObserver 70 1 to 4 Hz output, RS422 and RS485
- WindSonic 75 0 to 75 m/s, 0.5 kg, low-cost additional reporting point
- MetConnect THP adds temperature, humidity and pressure at the same location
Runway stop-end and secondary masts
Stop-end and secondary masts fill in the picture the threshold sensor cannot see, and they sit where access needs a runway closure.
- WindObserver 70 no moving parts to seize between inspections
- WindObserver 90 0 to 90 m/s where exposure demands the wider range
- WindSonic M heated aluminium body, operating to -40 degrees C
Approach and departure path
Approach decisions depend on wind, visibility and precipitation reported from the ground, at the rate the procedure needs.
- WindObserver 70 the model that carries FAA and CAA acceptance
- MaxiMet GMX501 wind, temperature, humidity, pressure and solar in one unit
- TruMet PW100 optical rainfall, 0 to 200 mm/hr, no moving parts
Control tower and ATIS reference
The tower display and the automated broadcast both trace back to one set of sensors, so the output format matters as much as the accuracy.
- WindObserver 70 RS422 and RS485, full or half duplex, 1200 to 38400 baud
- MetConnect One ASCII, Modbus RTU and ASCII, NMEA 0183 and SDI-12 v1.3
- MetConnect THP pairs with a heated remote anemometer for cold sites
AWOS and automatic weather station enclosure
The field station is where the parameters come together, and WMO siting wants them separated by height rather than stacked in one housing.
- MetConnect THP separates sensors by height, accepts Pt100 and analogue inputs
- WindObserver 70 the remote anemometer feeding the station
- TruMet PW100 contact-closure rainfall input, 0.1 mm resolution
Airfield wind reference and sensor siting
A wind sensor is only as good as where it sits. Obstructions, buildings and mast height all change what the instrument reports.
- WindObserver 75 open head holds accuracy as the flow angle increases
- WindSonic 60 0 to 360 degrees with no dead band
- MetConnect One integrated WindSonic with T, H and P in one hub
Helipad and HEMS operations
Rotary wing operations turn round fast and often at night, and the wind limit is checked at the pad rather than the main met station.
- WindObserver 70 heated, IP66, 316 stainless, icing tested to MIL-STD-810F
- MaxiMet GMX501 compact station where pad space and cabling are tight
- WindSonic M heated, 0.9 kg, for a lightweight pad-side reference
De-icing pad and winter operations
De-icing is scheduled against temperature, humidity and precipitation, and the holdover time depends on getting those three right.
- MetConnect THP temperature to 0.2 degrees C, humidity to 1.5 percent RH
- MaxiMet GMX550 wind, T, H, P and rainfall, optional heating to -40 degrees C
- WindSonic M heated wind sensor for the pad itself
Aircraft stands and ground handling
Ramp crews work through the hottest part of the day in high-visibility clothing, and heat stress is measured as WBGT rather than air temperature.
- MaxiMet GMX552 WBGT heat stress with wind, T, H and P, 1.29 kg, IP66
- MaxiMet GMX500 wind, temperature, humidity and pressure for the apron
- MetConnect One where the stand needs third-party sensor inputs too
Hangar doors and maintenance areas
Large hangar doors carry a wind limit, and the interlock needs a measurement it can act on rather than a forecast.
- WindSonic 60 0 to 60 m/s, 0.5 kg, straightforward to mount on a door frame
- WindObserver 65 1, 2, 4, 5, 8 or 10 Hz output for faster interlocks
- Blade position sensors non-contact door and actuator position feedback
Fuel farm and hydrant system
Fuel storage is a certified hazardous area, so the wind sensor has to carry the certification before anything else about it matters.
- WindObserver IS ATEX, IECEx and UKEX certified, EN 60945:2002 for EMC
- LevelPro capacitive liquid level sensing with no moving parts
- LevelLite level measurement for smaller tanks and bowsers
Airfield construction and crane operations
Cranes working airside stop at a defined wind speed, and the reading has to hold up if the stoppage is ever questioned.
- WindSonic 75 0 to 75 m/s, full-range accuracy published
- WindObserver 90 0 to 90 m/s for exposed lifts
- MaxiMet GMX200 wind only, 0.5 kg, for a temporary works mast
UAV operations and airspace monitoring
Drone inspection and BVLOS work at an airfield runs to its own wind limits, on airframes where every gram counts.
- WindUltra compact 2-axis, IP69k, low power, built for mobile platforms
- WindSonic 60 0.5 kg ground reference for launch and recovery
- MaxiMet GMX200 portable wind reference for a temporary operating site
Environmental and air quality monitoring
Noise and emissions reporting is only as defensible as the meteorology recorded alongside it, and that record has to run for years.
- MetConnect THP WMO-compliant separation, two analogue inputs and a Pt100 input
- MaxiMet GMX551 wind, T, H, P, solar and rainfall in one compact station
- TruMet PW100 optical rainfall, 5 percent accuracy, no tipping bucket to clear
Ground support equipment condition
Tugs, loaders and steps fail on the stand rather than in the workshop, and oil tells you what is wearing before the failure does.
- WearDetect oil debris sensing for wear particles in lubricated equipment
- LevelLite fluid level in fuel, oil and hydraulic tanks
- Blade position sensors non-contact position feedback with no wearing parts
Calibration and verification
A reported wind speed is only defensible if it is traceable, and an accredited certificate is what closes the question.
- UKAS-accredited air velocity calibration traceable certification for anemometers and probes
- Multi-parameter calibration six parameters, equipment from any manufacturer
- Recalibration scheduling intervals, reminders and turnaround
Two measurements, both awkward to make safely
Wind speed and direction at a fuel farm are the inputs to a dispersion assessment. If vapour is released, the direction it travels decides which stands are cleared and which route the response takes, and that decision is made in the first minutes.
The instrument making that measurement sits inside the classified area, which is why the intrinsically safe variant matters. The WindObserver IS carries ATEX, IECEx and UKEX certification for exactly this position.
Liquid level is the other measurement, and it is doing several jobs at once. It is the stock figure the logistics chain plans against, the reading that confirms a delivery, and the limit that prevents an overfill.
Capacitive level sensing suits it because there is no float. A mechanical float in aviation fuel is a moving component in a location that is expensive to access, in a fluid that will find any imperfect seal.
The certification has to come first
An intrinsically safe instrument is designed so that the energy available in the circuit cannot ignite the atmosphere it sits in, and that design is certified rather than asserted.
The WindObserver IS is the intrinsically safe variant of the WindObserver range, carrying ATEX, IECEx and UKEX certification. It measures wind speed and direction ultrasonically, so there is no rotating element to seize inside an area nobody wants to enter for maintenance.
Certified for the area it sits in
View WindObserverLevel without a moving part
A fuel tank measurement is checked against deliveries and against the stock figure, so an error is noticed commercially before it is noticed operationally. That argues for a sensor with no moving part in the measurement to wear.
Gill capacitive level sensors have no float and fully sealed solid-state electronics. LevelPro is corrosion-resistant stainless at IP66 and IP68 with 0-10 V or 4-20 mA output, RS232 for configuration, and LevelSlick adds a FEP coating for the liquids that defeat everything else.
No float, nothing to jam
Explore level sensorsA fuel farm is audited on both counts
Stock reconciliation and safety case review both work from recorded measurement, and they ask different questions of the same instrument: was it accurate, and was it appropriate for the area it was installed in.
Certification answers the second question and calibration answers the first. Both are specification decisions, and both are considerably cheaper to make correctly at the start than to retrofit.
Labcal is an independent UKAS-accredited laboratory operating to ISO/IEC 17025:2017, calibrating equipment from any manufacturer across pressure, temperature, humidity, air velocity and flow.
What a fuel installation measures
Certified wind measurement for the classified area, capacitive level sensing for the tanks, and the accredited calibration behind both.
Classified area measurement
WindObserver
Heated 316 stainless open-head 2-axis anemometer
The WindObserver IS variant carries ATEX, IECEx and UKEX certification for installation inside the classified area itself.
WindSonic
Lightweight 2-axis ultrasonic anemometer
Lightweight measurement for boundary and unclassified positions around the installation, where mounting simplicity matters.
MaxiMet
All-in-one weather station, no moving parts
Temperature, humidity and pressure alongside wind, for the dispersion picture and the operational record.
Tanks and fluids
Level sensing
Capacitive liquid level sensors
Continuous level in bulk tanks and hydrant systems with no float, fully sealed electronics and output straight into the stock system.
WearDetect
Oil debris sensor
Oil debris monitoring on the pumps and drives that move the fuel, where a failure stops the whole refuelling operation.
TruMet PW100
Infrared optical rain gauge
Optical rainfall measurement feeding bund capacity and interceptor decisions, with no mechanism to block.
Where hazardous-area measurement does the work
Bulk storage
Tank level for stock and overfill protection, with certified wind measurement for the dispersion case.
Distribution
Level and condition measurement across a system that has to be available whenever the airfield is.
Stands and pads
Wind direction where a release would be responded to, measured inside the classified area.
Containment
Level and rainfall measurement supporting containment capacity and discharge decisions.
Rotating plant
Oil debris and level monitoring on the machinery that moves the fuel.
Safety case
Measurement whose certification and calibration both stand up when the case is examined.
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 fuel installation carrying anemometers, pressure instruments, thermometers, temperature and humidity probes and data loggers, a single accredited laboratory keeps the whole estate on one 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 the reading out of the classified area
Measurement inside a classified area has to reach systems outside it, and the interface is part of the safety design rather than an afterthought.
Gill supports environmental monitoring, industrial sensing, embedded electronics and systems integration, so fuel operators, contractors and systems integrators can bring certified measurement into stock, control and emergency systems.
Whether the requirement is 4-20 mA into a tank gauging system, Modbus into a site network, or a serial string into an operational display, Gill engineers can support integration from specification through commissioning.
Outputs and options
- Modbus RTU : Site systems and SCADA
- SDI-12 & serial : Loggers and remote telemetry
- 4-20 mA & 0-10 V : Existing analogue channels
- Traceable calibration : So the record holds up on review
What the specification looks like in practice
Certified for the area
The WindObserver IS variant carries ATEX, IECEx and UKEX certification for installation inside a classified area.
Nothing rotates, so nothing seizes
Ultrasonic measurement removes the rotating element, which matters most in a location maintenance access is restricted in.
Level measured without a float
Capacitive sensing has no moving component in the fuel, with fully sealed solid-state electronics.
Built for the fluid
LevelPro in corrosion-resistant stainless at IP66 and IP68, and LevelSlick FEP coated for particulate, viscous and corrosive liquids.
Into the systems that already exist
0-10 V, 4-20 mA, RS232 and Modbus outputs feed tank gauging, control and operational displays.
Evidence for the safety case
Independent UKAS-accredited calibration across six parameters, for equipment from any manufacturer.
Questions about fuel farms and hazardous areas
The WindObserver IS is the intrinsically safe variant of the WindObserver range and carries ATEX, IECEx and UKEX certification.
Certification requirements depend on the zone and the classification, so the specification should be confirmed against the area classification for the installation.
Because there is no float. A mechanical float is a moving component inside the fluid, in a location that is expensive to access, and its reading changes as it wears.
LevelPro provides stainless steel construction with IP66 and IP68 protection and 0-10 V or 4-20 mA output, RS232 for configuration.
A continuous level measurement can feed both the stock figure and an overfill limit, though the safety function itself is usually specified separately according to the installation requirements.
Wind speed and direction are the inputs to a dispersion assessment. If vapour is released, direction decides which areas are cleared and which route a response takes, and that is decided in the first minutes.
LevelSlick uses a FEP-coated construction intended for particulate, viscous and corrosive liquids. The fluid properties and the installation should be reviewed as part of sensor selection.
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.
Speak to our team
Tell us what you need to measure, where and under what conditions. We’ll help you work out the appropriate approach.
We aim to respond in one working day.