From the fresh water tank to the sump
Know exactly how much water is in the tank, whether it is fresh water on a vessel or grey water heading for the sump. Gill capacitive water level sensors measure continuously along the probe, with no moving parts in the sensing mechanism, delivering dependable level measurement in clean and difficult water alike.
Water looks simple until it is in a tank
Fresh water tanks on vessels, vehicles and remote sites need a dependable reading so supplies do not run out. Grey water, wastewater and sumps add suspended solids, grease and biological growth that coat floats and jam switches. Water is also electrically conductive, which changes how a capacitive probe has to be built.
Clean tanks. Fresh water tanks need a sealed, corrosion-resistant sensor that will sit in water for years. LevelPro is built in stainless steel and sealed to IP66 and IP68.
Dirty tanks. Grey water and wastewater need a probe surface that sheds deposits, which is why LevelSlick uses a non-stick FEP probe.
Your liquid.
The right fit.From tank dimensions to output and supply voltage, share the details and our engineers will help you find the sensor configuration that fits.
Dependable water level measurement, without the moving parts
Water looks simple until it is in a tank. Fresh water tanks need a reading you can trust so supplies never run out, while grey water and wastewater carry solids, grease and growth that coat floats and jam switches.
Gill capacitive water level sensors take a different approach, measuring water continuously along a probe rather than relying on a float to indicate the level. As the water rises or falls, the capacitance around the probe changes, and the sensor converts that change into a level reading for a display, controller or monitoring system. LevelPro suits clean tanks, while LevelSlick’s non-stick FEP probe is built for dirty and conductive water. With no float, arm or reed switch in the measurement mechanism, there are fewer mechanical components to foul or wear.
Continuous measurement. Track water level along the probe, capturing supply, use and waste as they happen rather than relying on discrete switching points.
Calibrated for the application. Factory calibration is matched to the probe length and intended application, helping deliver a water level reading suited to the tank being monitored.
Outputs to suit your system. Depending on the model, choose from voltage, current, resistive or RS232 outputs for integration with displays, controllers and monitoring systems.
Not all water level sensors see the tank the same way
Some measure down to the surface. Others follow a float. Gill capacitive water level sensors take a different approach, measuring continuously along a probe immersed in the water. That distinction matters when you’re choosing a sensor for a fresh, grey or waste water tank, where solids, foam, condensation and the space available all influence which technology makes sense.
| Method | Our approachGill capacitive | Radar | Ultrasonic | Float or reed switch |
|---|---|---|---|---|
| How it reads the level | Reads the change in capacitance along a probe in the liquid | Times a microwave pulse reflected off the surface from above | Times a sound pulse echoing off the surface from above | A float rides the surface and moves an arm, stem or switch |
| Moving parts | None | None | None | Float and pivot or stem |
| Foam on the surface | Measures the liquid along the probe, not the top of the foam | Heavy foam can weaken the echo | Foam can absorb the echo | The float can sit on the foam |
| Vibration and slosh | Continuous signal the receiving system can average | A moving surface can scatter the echo | A moving surface can scatter the echo | The float swings and the reading jumps |
| Small or cramped tanks | One compact probe through a single fitting | Needs headroom and a clear beam path | Needs headroom for its dead zone | Needs room for the float to travel |
| Shaped tanks | Calibrated against the tank profile | Set up for the vessel geometry | Set up for the vessel geometry | Arm geometry limits accuracy |
| Watch out for | Calibration to the liquid, and a probe matched to conductive or fouling liquids | Weaker echoes from low-dielectric liquids such as fuels and oils, false echoes from internal structures, size and cost | Vapour, condensation, temperature layers and internal obstructions | Sticking, wear, deposits and readings in steps |
| Where it fits best | Vehicle, plant, marine, UAV and machinery tanks | Large storage tanks and process vessels | Open tanks, sumps and channels with a calm surface | Simple, low-cost tanks and alarms |
Why engineers choose Gill capacitive
- Nothing moves, so nothing sticks, wears or fouls
- Reads the liquid, not the foam or the ripple on top
- One compact probe that fits tanks other methods cannot
- Calibrated to the liquid and to the shape of the tank
If your vessel is better served by a non-contact method, our engineers will say so plainly.
Engineered for tanks that don’t fit the mould
Fresh and grey water tanks are moulded to fit hulls, chassis and plant rooms, not designed as neat rectangles. That makes accurate water measurement more complex: the same change in water height can represent very different changes in volume, depending on the tank’s geometry. Gill level sensors can be configured to account for the tank’s shape, translating measured level into a more meaningful indication of how much water it contains.
Tank profiling across the range. GSLevel, Gill’s configuration software for its liquid level sensor range, includes tank profiling to support volumetric output rather than height alone.
Profile it your way. Use the configuration wizard or upload a CSV file describing the tank’s cross-section.
Calibrated to your tank. LevelDefend and custom level sensors can be calibrated to the customer’s tank geometry, helping deliver water level measurements suited to the installation.
Which water level sensor suits your tank?
LevelPro suits clean fresh water tanks. LevelSlick is built for grey water, wastewater and other dirty or conductive water, and Gill builds custom sensors where neither fits.
LevelPro
Best for general fuel, oil, water and coolant tanks
LevelPro is the general-purpose sensor in the Gill range, built in corrosion-resistant stainless steel and fully sealed. It measures fuel, oil, water and other liquids continuously in vehicles, tanks and industrial equipment, with 0 to 10 V or 4 to 20 mA output and RS232 for configuration.
- Stainless steel
- IP66 and IP68
- 0 to 10 V
- 4 to 20 mA
- RS232
- Tank profiling
LevelSlick
Best for dirty, viscous or conductive liquids
LevelSlick is designed for challenging conductive liquids: liquids carrying particles or suspended matter, viscous liquids and corrosive liquids. Its non-stick FEP probe resists build-up, and it offers tank profiling with full and empty alarms.
- Non-stick FEP probe
- Up to 2 m
- -40 °C to +85 °C
- Tank profiling
- Full and empty alarms
Custom level sensors
Best when no standard model fits the tank
Gill designs custom level sensors where the tank, mounting, temperature or interface rules out a standard model. Flanges, probe length, cable, sealing and outputs can all be changed, and extra measurements such as temperature can be designed into the probe.
- Custom flange
- Custom probe length
- Integrated temperature option
Frequently asked questions
Water level in a tank can be measured without a float using a capacitive level sensor, which reads the change in capacitance along a probe as the water rises and falls. A Gill capacitive water level sensor reports the level continuously along the probe length and has no moving parts in the tank to foul or jam. The probe construction is chosen for the water, with LevelPro for clean tanks and LevelSlick for dirty or conductive liquids with solids.
A Gill level sensor can measure an irregular-shaped tank because tank profiling turns the level reading into a volumetric output. GSLevel, the configuration software for the Gill liquid level sensor range, profiles the tank through a configuration wizard or from a CSV file of the tank’s cross section. LevelDefend and custom builds are calibrated to the customer’s tank, so a tank drawing at enquiry lets an engineer confirm the approach.
LevelSlick is the Gill level sensor for grey water, wastewater and other challenging conductive liquids that carry particles, suspended matter or grease. Its non-stick FEP probe resists build-up, probes run up to 2 m, and it offers tank profiling with full and empty alarms. LevelSlick operates from -40 °C to +85 °C with voltage, current or resistive output.
Gill level sensors are used to monitor the fresh water, grey water and blackwater tanks carried on marine craft. LevelPro suits clean fresh water tanks, while LevelSlick suits grey water and blackwater where solids and deposits are present. Probe length, mounting and output are matched to each tank, so a vessel can use one family of sensors across its tanks.
LevelPro and LevelSlick are both Gill capacitive water level sensors, built for different water. LevelPro is the robust stainless steel sensor for clean water, such as fresh water tanks. LevelSlick has a non-stick probe for grey water, wastewater and other conductive liquids that carry particles, suspended matter or grease, with probes up to 2 m and full and empty alarms. Naming the water type at enquiry settles which model fits.
Gill water level sensors offer a choice of outputs, and the choice depends on the model. LevelPro provides 0 to 10 V, 4 to 20 mA or RS232. LevelLite adds CAN alongside RS232, voltage and current options, which suits vehicle networks and telematics. LevelSlick offers voltage, current or resistive output, and LevelDefend is built with the output the customer’s system requires. A 4 to 20 mA current output needs a 250 ohm load resistor.
A Gill water level sensor in the LevelPro or LevelLite range runs from a +5 to +32 V DC supply, which covers 12 V and 24 V vehicle and plant systems. One LevelPro output type uses a +9 to +32 V DC supply instead. LevelSlick and LevelDefend supply requirements are set out on the datasheet or the build specification, so confirm the figure for the model and configuration being specified.
Talk to an engineer
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.
What our engineers will ask about
- What is in the waterFresh, grey, black or process water each point to a different probe. Describe the solids, grease or chemicals present.
- Probe length and threadLevelSlick probes run up to 2 m with a BSP 1.25 inch thread. Share the tank depth and fitting so the probe matches.
- Tank shape and alarmsTank profiling gives a volumetric output in shaped tanks, and LevelSlick adds full and empty alarms.
- OutputLevelSlick offers voltage, current or resistive output and LevelPro 0 to 10 V or 4 to 20 mA. Match the output to the receiving system.