
Bulk fuel is a classified area
wherever it is parked
Capacitive level measurement for stock and safety, with intrinsically safe wind sensing for the classified areas around it, on installations from permanent depots to a fuel farm raised last week.
The level reading is a logistics decision first
Bulk fuel level is a stock figure before it is anything else. It decides resupply, it decides what can be committed, and it is read by people planning an operation rather than by people maintaining a tank.
It is simultaneously a safety measurement. The same reading prevents an overfill and supports the case that a classified area is being managed properly, and the two uses put different demands on the same instrument.
Then the classification narrows the field. Equipment installed in or around bulk fuel has to carry the right certification, and that decides the shortlist before accuracy, output or cost is discussed.
Every operational decision starts at a measurement point
Switch between land, sea and air: vehicles, perimeters and deployable sites; ship’s wind, flight decks and machinery; uncrewed aircraft, landing points, airfields and ranges.
Mast head instruments
The top of a mast is the right place for the measurement and the wrong place for anything that needs a rigger.
- WindObserver 75 316 stainless open head, heated, IP66
- WindSonic 75 0 to 75 m/s, 0.5 kg, low mast loading
- WindMaster Pro 3-axis to 32 Hz where turbulence matters
Lower mast and reference levels
A second level turns one reading into a profile, which is what tells you whether the top sensor is seeing the site or the mast.
- WindSonic 60 0 to 60 m/s, economical per additional level
- MetConnect THP WMO-compliant separation of sensors by height
- MaxiMet GMX500 wind, temperature, humidity and pressure in one unit
Perimeter and boundary
A perimeter runs for kilometres through terrain nobody visits, so power draw and maintenance interval decide what can actually be installed.
- MaxiMet GMX200 wind only, 0.5 kg, minimal power
- MetConnect THP 5 to 30 V DC, under 70 mA at 12 V DC
- WindSonic 60 no moving parts to service along the line
Gates, barriers and access control
A barrier that cannot prove its position stops the traffic it exists to control, and it cycles all day.
- Blade position sensors non-contact inductive, unlimited-life feedback
- Blade360 contactless rotary position for barrier arms
- Blade Dual Output a second independent channel where redundancy is required
Vehicle fuel and fluid level
Range is a fuel calculation, and a float gauge on a vehicle crossing rough ground is telling you about the terrain, not the tank.
- LevelDefend military-grade, 6082 T6 anodised aluminium, sealed solid state
- LevelLite lightweight aluminium, IP68, voltage or current output
- LevelPro stainless steel, IP66 and IP68, 0-10 V or 4-20 mA, RS232 for configuration
Vehicle-mounted environmental sensing
A crew making a decision from a vehicle needs conditions where the vehicle is, not where the met station is.
- WindUltra compact 2-axis, IP69k, low power, built for mobile platforms
- MaxiMet GMX200 wind only, 0.5 kg, quick to mount
- MaxiMet GMX500 wind, temperature, humidity and pressure in one housing
Deployable and expeditionary sites
A deployable site is set up by people with other jobs to do, in weather, so setup time and configuration are part of the specification.
- MaxiMet GMX200 0.5 kg, wind only, one cable, one output string
- MaxiMet GMX551 wind, T, H, P, solar and rainfall in one housing
- MetConnect One MetSet and MetView configuration and logging software
Field shelters and accommodation
Shelter heating, ventilation and condensation all follow temperature and humidity, and the record matters when equipment inside starts failing.
- MaxiMet GMX300 temperature, humidity and pressure, no wind
- MetConnect THP temperature 0.2 degrees C, humidity 1.5 percent RH
- MaxiMet GMX400 temperature, humidity, pressure and rainfall
Turret, hatch and actuator position
Position feedback on a platform runs through vibration, shock and grit, and a contacting sensor is a wear item somebody has to change in the field.
- Blade position sensors non-contact inductive, no wearing parts
- Blade60 contactless linear position feedback
- Blade25 contactless linear position for compact installations
Fuel handling and bowsers
Bulk fuel is a classified area wherever it is parked, and the stock figure is a logistics decision before it is a safety one.
- WindObserver IS ATEX, IECEx and UKEX certified, EN 60945:2002 for EMC
- LevelPro capacitive level, fully sealed solid-state electronics
- LevelDefend military-grade level to customer requirement
Stand-off and remote sensing positions
The useful measurement position is often the one you cannot get power or a person to reliably.
- MetConnect THP 5 to 30 V DC, SDI-12 v1.3, Modbus, NMEA 0183
- MaxiMet GMX200 0.5 kg, minimal power, single output string
- WindUltra IP69k, low power, built for harsh mobile use
Precipitation and going conditions
Rainfall drives ground conditions, mobility and river crossing, and a gauge that blocks stops reporting during the event you care about.
- TruMet PW100 optical, 0 to 200 mm/hr, no moving parts to block
- MaxiMet GMX603 integrated optical rainfall, 5 percent or better
- MaxiMet GMX551 rainfall alongside wind, T, H, P and solar
Heat stress and human performance
People work in protective equipment in heat, and air temperature alone understates what that does to them by a wide margin.
- MaxiMet GMX552 WBGT heat stress with wind, T, H and P, 1.29 kg, IP66
- MaxiMet GMX500 wind, temperature, humidity and pressure
- MetConnect One where third-party sensors join the same station
Calibration and traceability
Acceptance testing, trials and incident investigation all rest on instruments somebody has to prove were right at the time.
- UKAS-accredited air velocity calibration traceable certification for anemometers
- Multi-parameter calibration six parameters, equipment from any manufacturer
- Recalibration scheduling intervals, reminders and turnaround
Ship’s wind at the mast head
A ship’s wind reading feeds navigation, flight operations and weapons meteorology, and it comes from a sensor on a mast that nobody climbs at sea.
- WindObserver 75 316 stainless, heated, IP66, Lloyd’s Register Type Approved
- WindObserver II Lloyd’s Register Type Approval and ABS Product Design Assessment
- WindObserver 90 0 to 90 m/s where the extreme wind case sets the specification
Bridge wing and navigation
On a moving platform, wind direction means little without the heading, so the sensor has to carry its own compass or take one from the ship.
- MaxiMet GMX560 wind, temperature, humidity and pressure with a 6-axis compass
- MaxiMet GMX260 wind with a 6-axis compass, 0.5 kg, IP66 and IP68
- WindUltra compact 2-axis, IP69k, for exposed positions
Flight deck launch and recovery
Helicopter launch and recovery limits are applied at the flight deck, on a platform that is itself moving, in airflow bent by the hangar and superstructure.
- WindObserver 70 heated, IP66, 316 stainless, Lloyd’s Register Type Approved
- MaxiMet GMX560 marine station with 6-axis compass, IP68
- WindObserver II ABS Product Design Assessed for marine service
Fuel, ballast and bilge level
A tank on a ship never sits still, so a float reports the sea state as much as the contents, and tanks are among the hardest places on board to reach.
- LevelDefend military-grade capacitive level, built to customer requirement for marine craft
- 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
Engines, gearboxes and generators
At sea, a machinery failure is fixed with what is on board, so wear has to be seen developing long before it becomes a breakdown.
- 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 the machinery system
Rudder, hatch and actuator position
Steering gear, hatches and actuators have to prove their position through salt water and vibration, where a contacting sensor is a wear item.
- Blade360 full 360 degree contactless position, IP67, sealed for temporary immersion (1 m for 30 min)
- Blade Dual Output a second channel where redundancy is required
- Blade60 contactless linear position to 60 mm
Uncrewed surface vessels
An uncrewed vessel carries its sensors through spray and green water with nobody to clear them, on a power budget set by the length of the mission.
- WindUltra IP66, IP68 and IP69k, low power, heated
- MaxiMet GMX260 wind with a 6-axis compass for moving platforms
- LevelLite lightweight aluminium fuel level, IP68, voltage or current output
Uncrewed air systems
On an airframe, every gram of sensor is endurance you do not get back, and the launch decision still needs a wind number.
- WindUltra compact 2-axis, IP69k, low power, built for mobile platforms
- LevelLite lightweight aluminium fuel level, IP68, voltage or current output
- WindSonic 60 0.5 kg ground reference for launch and recovery
UAV launch and recovery
The launch decision is a wind number taken at the launcher, and the ground reference has to be carried in with everything else.
- WindSonic 60 0.5 kg ground reference for launch and recovery
- MaxiMet GMX200 wind only, 0.5 kg, one cable and one output string
- MaxiMet GMX500 wind, temperature, humidity and pressure in one unit
Rotary wing operations
Rotary wing crews work to wind and turbulence limits checked at the landing point, often at night and off a prepared surface that was a field last week.
- WindObserver 70 heated, IP66, 316 stainless, marine type approved
- MaxiMet GMX501 compact station where pad space and cabling are tight
- WindSonic M heated, 0.9 kg, for a pad-side reference
Airframe actuator position
On an airframe, position feedback has to be light, survive vibration for the life of the aircraft and report its own health.
- Blade position sensors non-contact, with unlimited mechanical life
- Blade25 contactless linear position to 25 mm
- Blade Dual Output a second channel where redundancy is required
Airfield surface wind
At a military airfield the runway wind feeds every take-off and landing, and the reading has to hold through icing and the long winters in between.
- WindObserver 70 accepted for FAA and CAA AWOS reporting
- WindObserver 75 heated head, icing tested to MIL-STD-810F
- MetConnect THP temperature, humidity and pressure at the same site
Ranges and ballistic meteorology
On a firing or test range, wind, temperature and pressure at the moment of the event feed the trajectory, and the trial is only as good as that record.
- WindObserver 90 0 to 90 m/s, 316 stainless, heated
- MaxiMet GMX500 wind, temperature, humidity and pressure in one unit
- WindMaster Pro 3-axis to 32 Hz where turbulence matters
Radomes and sensor installations
A fixed installation is judged on availability over years, in a place where a maintenance visit is a task in its own right.
- WindObserver 90 0 to 90 m/s, 316 stainless, IP66, no moving parts
- WindObserver 75 heated head, icing tested to MIL-STD-810F
- MetConnect THP temperature, humidity and pressure at the same site
Stock, safety and certification on one instrument
A capacitive level sensor measures continuously with no float, which suits both uses. The stock figure is a reading rather than a dip, and the safety limit is a threshold on the same continuous measurement rather than a separate mechanical device.
Construction is where the application decides the sensor. LevelPro is corrosion-resistant stainless at IP66 and IP68, LevelSlick adds a FEP coating for particulate, viscous and corrosive liquids, and LevelLite is lightweight aluminium at IP68 with voltage or current output where weight matters on a vehicle or a demountable tank.
Wind measurement sits alongside it for the dispersion case. If vapour is released, direction decides the response, and the instrument making that measurement is inside the classified area itself.
The WindObserver IS is the intrinsically safe variant of the range, carrying ATEX, IECEx and UKEX certification, and it measures ultrasonically so there is no rotating element to seize where maintenance access is restricted.
Stock you can read without dipping
A dip is a visit, a person and a moment in time. A continuous level measurement is a figure that is current whenever the logistics chain asks for it, from a tank that may be a long way from anyone.
Gill capacitive level sensors have no float and fully sealed solid-state electronics, with 0-10 V, 4-20 mA, RS232 and CAN outputs depending on the model, feeding stock systems, vehicle networks and control directly.
A figure, not a visit
Explore level sensorsCertified before it is compared
Certification is not a feature to weigh against others, it is the gate. An instrument without the right approval for the area classification is not a compromise, it is excluded.
The WindObserver IS carries ATEX, IECEx and UKEX certification for installation inside the classified area. Requirements depend on the zone, so the specification should be confirmed against the classification for the particular installation.
Certified for the area it sits in
View WindObserverFuel is reconciled and audited
Stock reconciliation, loss investigation and safety case review all work from recorded level measurement, and they ask different questions of the same instrument: was it accurate, and was it appropriate for where it was installed.
Calibration answers the first and certification answers the second, and both are considerably cheaper to specify correctly than to retrofit into a live installation.
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 and logistics installation measures
Capacitive level sensing for the tanks, certified wind measurement for the classified area, and condition monitoring on the plant that moves the fuel.
Tanks and fluids

Level sensing
Capacitive liquid level sensors
Continuous level with no float, in stainless, FEP coated or lightweight aluminium depending on the fluid, the tank and whether it moves.

WearDetect
Oil debris sensor
Ferrous debris monitoring on the pumps and drives that move the fuel, where a failure stops the whole distribution.

Blade position sensors
Non-contact inductive position sensing
Non-contact position feedback on valve and actuator mechanisms, sealed to IP67 for temporary immersion (1 m for 30 min).
Classified area and site

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.

WindSonic
Lightweight 2-axis ultrasonic anemometer
Lightweight measurement for boundary and unclassified positions around the installation.

MaxiMet
All-in-one weather station, no moving parts
Temperature, humidity and pressure alongside wind, for the dispersion picture and the operational record.
Where fuel and infrastructure measurement does the work
Bulk storage
Continuous tank level feeding stock systems, with certified measurement in the classified area.
Temporary installations
Level measurement on demountable tanks raised for an operation and recovered afterwards.
Mobile fuel
Lightweight level sensing with CAN output into vehicle and logistics networks.
Refuelling points
Level and wind measurement where refuelling happens alongside aircraft or vessels.
Distribution plant
Condition and position 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 stock figure into the planning system
A level reading is used by a logistics planner, a safety system and sometimes a vehicle network, and it has to reach all of them from inside or beside a classified area.
Gill supports environmental monitoring, industrial sensing, embedded electronics and systems integration, so defence users, contractors and equipment manufacturers can bring level and condition measurement into existing systems.
Whether the requirement is 4-20 mA into a tank gauging system, CAN into a vehicle network, Modbus into site control, or a configurable sensor embedded into an OEM build, Gill engineers can support integration from specification through commissioning.
Outputs and options
- CAN & RS232 : Vehicle and logistics networks
- 4-20 mA & 0-10 V : Tank gauging and existing channels
- Modbus RTU : Site control and SCADA
- Traceable calibration : So stock and safety records hold up
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.
Level measured without a float
Capacitive sensing has no moving component in the fuel, with fully sealed solid-state electronics.
Construction matched to the fluid
LevelPro in stainless at IP66 and IP68, LevelSlick FEP coated, and LevelLite in lightweight aluminium at IP68 for mobile tanks.
A figure rather than a dip
Continuous measurement means the stock number is current whenever the planner asks for it.
Nothing rotates in the classified area
Ultrasonic wind measurement removes the rotating element where maintenance access is restricted.
Evidence for both audiences
Independent UKAS-accredited calibration across six parameters, for equipment from any manufacturer.
Questions about fuel, logistics and infrastructure
It depends on the fluid, the tank and whether it moves. LevelPro provides stainless steel construction with IP66 and IP68 protection, LevelSlick adds a FEP coating for particulate, viscous and corrosive liquids, and LevelLite is lightweight aluminium at IP68 with voltage or current output where weight matters.
The WindObserver IS is the intrinsically safe variant of the WindObserver range and carries ATEX, IECEx and UKEX certification.
Requirements depend on the zone and the classification, so the specification should be confirmed against the area classification for the installation.
A continuous level measurement can feed both a stock figure and an overfill threshold, though the safety function itself is usually specified separately according to the installation requirements.
LevelLite is the lightweight aluminium option at IP68 with voltage or current output, which suits mobile and demountable installations where weight and vehicle integration both matter.
A float is a moving component inside the fluid whose reading changes as it wears, in a location that is often difficult to access. Capacitive sensing has no float and fully sealed electronics.
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.





































