Explore our range of intrinsically safe (IS) submersible hydrostatic level sensors, designed for accurate liquid level measurement in hazardous environments. These sensors are certified for use in Zone 0 and Zone 1 classified areas, ensuring safe and reliable operation in the presence of flammable gases, vapors, and dust.
LMP307 Submersible Level Transmitter - Submersible level transmitter for measuring liquid level with a 4-20mA current loop or a 0-10V voltage output plus optional ATEX approval for intrinsically safe use in hazardous areas in ranges from 1mH2O up to 250mH2O. The LMP307 is suitable for use on potable water with no leaching, and can be supplied with a drinking water certificate according to DVGW and KTW.
LMK458 Marine Approved Hydrostatic Level Transmitter - Marine approved level transmitter with 4-20mA output for measuring level of contents inside ship ballast, fuel, liquid cargo or wastewater tanks
LMK382 Low Range IP68 Waste Water Level Transmitter - Submersible Low Range waste water level transmitter with intrinsically safe option for monitoring the level of sewage and effluent in water treatment plants.
LMK307 Submersible Waste Water Level Sensor - Submersible waste water level sensor with optional intrinsic safety certification for monitoring the level of sewage and effluent in water treatment plants.
LMK457 Marine Approved Level Transmitter - Marine approved level transmitter with 4-20mA current loop output for shipbuilding with optional all CuNiFe construction for sea-water compatibility in ranges from 0.4 mH2O to 250mH2O gauge.
LMP 308 Removable Waterproof Cable Connection Water Level Sensor - Groundwater, tank & reservoir water level detachable submersible cable hydrostatic liquid level sensor for multiple municipal water level measurement locations.
- Zone 0 ATEX borehole water level sensor for flammable atmospheres
- Leachate holding tank submersible level sensor for 5 metre depth
- Sewage level transmitter for submerging in low depths to 5 psi
- IP68 sewage level transmitter with 6m/20ft range, ATEX IS approval and FEP cable
- Fleet management system submersible 3000mm height petrol tank level ATEX rated pressure sensor
- Retrofitting ship bubbler tank gauging system with 22mm submersible level probe
Send us your enquiry to discuss your Hazardous Area Submersible Hydrostatic Liquid Level Sensors application with a product specialist, and they will help you select the best option to suit your specific requirements.
Submersible hydrostatic level sensors are essential tools for measuring liquid levels in a variety of industrial applications. They are particularly well-suited for use in hazardous areas where explosive atmospheres may be present. These sensors operate on the principle of hydrostatic pressure, where the pressure exerted by a liquid column is directly proportional to its height. By measuring this pressure, the sensor can accurately determine the liquid level.
Product Advantages
Our hazardous area submersible hydrostatic liquid level sensors offer a comprehensive suite of key advantages engineered to deliver uncompromising performance, high operational safety, and minimal long-term maintenance across demanding industrial environments. Below is an overview of the core benefits provided by this sensor range, from certified explosion protection to versatile system compatibility.
Intrinsically Safe Certification
Our sensors are fully certified to satisfy the stringent requirements of ATEX, IECEx, and other globally recognized safety standards for installation in hazardous environments. By limiting electrical and thermal energy levels, these intrinsically safe designs guarantee safe, reliable operation in Zone 0 and Zone 1 classified areas where potentially explosive gas, vapor, or dust mixtures are continuously or periodically present.
IP68 Submersible Construction
Featuring an exceptionally rugged IP68-rated seal and environmental encapsulation, these sensors completely prevent the ingress of liquids, humidity, particulates, and aggressive contaminants. The heavy-duty housing and cable assemblies are optimized for continuous, deep-water immersion, ensuring unwavering structural stability and long-term signal accuracy even under harsh underwater pressure conditions.
Corrosion-Resistant Materials
Constructed using high-grade stainless steel, high-purity ceramics, and specialized elastomeric seals or titanium options, these devices resist chemical attack and degradation. Whether exposed to saline water, aggressive leachates, sewage, or organic solvents, the durable material construction prevents pitting, stress corrosion, and material fatigue to maximize operational lifespan.
Easy Installation and Low Maintenance
Hydrostatic level probes offer straightforward deployment simply by being suspended or lowered directly into a tank, pit, or borehole without requiring complex wall mountings or extensive structural modifications. Because they feature solid-state sensing diaphragms with no moving mechanical components, they drastically reduce maintenance demands, lower risk of fouling, and minimize total cost of ownership.
High Long-Term Stability and Accuracy
Incorporating advanced piezoresistive silicon or capacitive ceramic pressure cells, these level transmitters feature excellent linear response curves and minimal thermal drift. Built-in temperature compensation ensures consistent, high-precision measurement output across fluctuating fluid temperatures, eliminating the need for frequent recalibration in critical processes.
Flexible Signal Outputs and System Integration
Equipped to output standard 2-wire 4-20mA current loops, low-power voltage signals, or digital protocols like HART and Modbus, these sensors easily integrate with standard PLCs, SCADA networks, and telemetry systems. This flexible connectivity facilitates real-time remote monitoring, automatic alarms, and seamless industrial automation integration.
Product Applications
Submersible hydrostatic level sensors are employed across a broad spectrum of heavy industries and municipal facilities to ensure continuous, accurate, and safe liquid level measurement within potentially explosive or highly hazardous environments. Designed to withstand continuous immersion and aggressive fluid properties, these devices provide crucial real-time monitoring across petrochemical storage, pharmaceutical manufacturing, landfill leachate containment, sewage treatment infrastructure, chemical processing, and marine ballast operations.
Petrochemical and Fuel Storage
In petrochemical refineries, fuel distribution terminals, and offshore platforms, submersible hydrostatic level sensors monitor storage tanks containing crude oil, refined gasoline, diesel fuel, and volatile hydrocarbons. Intrinsically safe certifications ensure safe operation in Zone 0 and Zone 1 classified areas where flammable vapors continuously persist. Maintaining highly precise hydrostatic head measurements is vital for inventory control, automated batching, leak detection, and overfill prevention systems.
Pharmaceutical and Fine Chemical Processing
These sensors play a critical role in maintaining precise liquid volumes during automated reaction cycles and solvent recovery processes within pharmaceutical facilities. They are deployed in mixing vessels, fermentation tanks, and ingredient holding containers containing organic solvents, reagents, and active pharmaceutical ingredients. Featuring hygienic flush diaphragms, corrosion-resistant housings, and smooth surface finishes, they facilitate stringent CIP/SIP cleaning protocols without compromising sanitary integrity.
Landfill Leachate Management
Monitoring leachate collection wells and holding lagoons in landfill sites is essential for environmental protection and regulatory compliance. Submersible hydrostatic level transmitters deliver continuous level data, enabling automated pump control systems to efficiently manage leachate extraction and prevent groundwater contamination. Built with rugged ceramic diaphragms and specialized FEP or PUR cables, these sensors resist aggressive chemical cocktails, heavy organic loading, and abrasive particulate suspension.
Wastewater and Sewage Treatment
Accurate level measurement is fundamental across municipal sewage networks and industrial wastewater treatment plants. Submersible sensors monitor influent wet wells, grit channels, digestion tanks, secondary clarifiers, and effluent discharge channels. Equipped with open flush ceramic or metallic diaphragms to prevent clogging from suspended solids and fibrous debris, they ensure continuous pump control, prevent sewer overflows, and support environmental compliance monitoring.
Chemical Manufacturing and Processing
Chemical manufacturing facilities utilize submersible pressure transmitters for continuous level monitoring in acid bulk storage, alkaline neutralization tanks, and hazardous chemical blend vessels. Constructed from specialized corrosion-resistant materials such as Hastelloy, Titanium, PTFE cables, and durable plastic housings paired with high-purity ceramic diaphragms, these sensors are particularly well-suited to withstand aggressive chemicals—including concentrated acids and strong alkalis—while maintaining high measurement stability and fast dynamic response.
Marine and Offshore Tank Gauging
Commercial vessels, cargo ships, and offshore drilling platforms rely on marine-certified submersible level transmitters for continuous monitoring of ballast water tanks, fuel oil storage, bilge water collectors, and liquid cargo holds. Featuring marine approvals (DNV, ABS, Lloyd’s Register) and corrosion-resistant CuNiFe or stainless steel bodies, these sensors withstand saltwater immersion, mechanical shock, and dynamic sloshing to ensure precise ballast balance and cargo safety.
Product Selection
Selecting the optimal hazardous area submersible hydrostatic liquid level sensor requires a thorough evaluation of environmental, physical, and electrical parameters. Key factors include matching hazardous zone certifications, evaluating chemical compatibility, defining the precise measurement range, accounting for required accuracy, ensuring system signal integration, verifying cable material durability, and evaluating operating temperature conditions to guarantee safe and reliable long-term performance.
Hazardous Area Classification
Ensure the sensor’s intrinsic safety certification precisely matches the hazardous area zoning requirements of your installation site. Verify whether the application demands Zone 0, Zone 1, or Zone 2 protection under ATEX or IECEx regulations, and ensure compatibility with the specific gas, vapor, or dust groups present in the working environment.
Media Compatibility and Liquid Type
Carefully evaluate the chemical composition and physical properties of the process fluid. Choose sensor housing, sensing diaphragm, and seal materials—such as 316L stainless steel, titanium, Hastelloy, or high-purity ceramics—that resist chemical attack, corrosion, abrasion, or organic fouling from seawater, wastewater, acids, or solvents.
Measurement Range and Submersion Depth
Select a hydrostatic sensor with a pressure range that closely encompasses the maximum anticipated liquid depth to maximize resolution and accuracy. Account for minimum and maximum liquid levels, potential fluid specific gravity variations, and overpressure ratings to withstand hydraulic spikes or deep submersion without calibration shift.
Accuracy and Thermal Stability
Determine the level of precision required for your monitoring, batching, or inventory process. Consider non-linearity, hysteresis, and repeatability metrics, as well as integrated temperature compensation features that prevent measurement drift across wide process temperature fluctuations.
Output Signals and Control System Integration
Choose an output signal format that seamlessly interfaces with existing PLCs, telemetry units, or SCADA architectures. Common options include standard 2-wire 4-20mA current loops, low-power voltage outputs, or digital communication protocols such as HART and RS485 Modbus for remote diagnostics and configuration.
Cable Material and Environmental Durability
The submersible cable must feature high tensile strength and chemical resistance suited to the immersion environment. Select cable jacketing materials like PUR, FEP, or PE that prevent fluid permeation, withstand tensile mechanical stress in deep wells, and include integral capillary tubes for atmospheric pressure compensation.
Process Temperature and Operating Conditions
Verify that all sensor components, internal electronics, and cable assemblies can withstand the full operating temperature range of the process fluid and ambient surroundings. Operating outside certified thermal limits can compromise sensor accuracy, seal integrity, and intrinsic safety ratings.
Product Installation
Proper installation of hazardous area submersible hydrostatic liquid level sensors is critical to ensuring long-term measurement accuracy, physical longevity, and strict compliance with explosion protection standards. Correct deployment involves careful handling during insertion, securing adequate cable strain relief, protecting atmospheric vent paths, positioning the probe away from hydrodynamic turbulence or settling solids, and completing robust electrical grounding. The following subsections outline essential installation practices to guarantee reliable performance and safe operation in hazardous environments.
Proper Lowering and Suspension Methods
When deploying the sensor into a deep borehole, well, or liquid tank, lower the unit slowly and smoothly to avoid sudden pressure shocks or physical impacts against vessel walls. Never drop or abruptly drop-test the transmitter, as mechanical shock can damage delicate ceramic or silicon sensing diaphragms. For deep submersion depths or high-flow environments, suspend the sensor using a dedicated stainless steel support wire or mounting clamp rather than relying solely on the signal cable for structural support.
Cable Handling and Strain Relief
Submersible cables contain delicate internal conductors and capillary tubes that require careful management during installation. Maintain minimum cable bend radiuses to prevent kinking, sheath tearing, or internal tube collapse. Utilize dedicated cable strain relief clamps, suspension grips, or junction box cord grips at the top of the wellhead or tank entry to secure the cable firmly without crushing or pinching the outer jacket.
Atmospheric Pressure Vent Tube Management
Gauge hydrostatic level sensors rely on an integrated capillary tube inside the cable assembly to equalize internal pressure with ambient atmospheric pressure. Ensure the vented end of the cable terminates in a clean, dry, non-submerged location or a vented junction box equipped with a desiccating filter or hydrophobic membrane filter. Moisture ingress into the capillary tube will cause measurement drift, corrosion, and permanent sensor failure.
Avoiding Turbulence and Sludge Buildup
Position the sensor probe away from direct fluid inlets, agitators, or pump discharge zones where dynamic hydraulic forces and turbulence can introduce artificial pressure spikes or cause probe swaying. In tanks or sump pits prone to heavy sediment, silt, or sludge accumulation, mount the sensor several inches above the vessel floor using a stilling pipe or anchor weight to prevent the sensing diaphragm from being buried or clogged by settled solids.
Grounding and Electrical Safety in Hazardous Areas
Install intrinsically safe transmitters via approved zener barriers or galvanic isolators located in safe areas according to ATEX/IECEx wiring regulations. Bond all metallic sensor housings, junction boxes, and cable shields securely to the local equipotential bonding system to eliminate ground loop voltage differentials and electrostatic charge buildup, ensuring complete explosion protection and personnel safety within hazardous zones.
Product Troubleshooting
Troubleshooting hazardous area submersible hydrostatic liquid level sensors requires systematic checks across signal integrity, supply power, pressure reference pathways, and structural seals. Common issues such as zero-point offset drift, erratic signal output, complete signal loss, or slow dynamic response can typically be isolated to cable capillary blockage, moisture ingress, sensing diaphragm fouling, or improper intrinsic safety barrier grounding. Promptly identifying these root causes helps prevent unnecessary downtime and ensures ongoing operational safety in hazardous environments.
Zero-Point Offset and Calibration Drift
If the sensor reads an unexpected non-zero level when the tank is empty or submerged depth does not match output values, inspect the internal vent capillary inside the cable assembly. Ensure the vent tube is not bent, pinched, or blocked by moisture, as restricted atmospheric pressure compensation directly causes zero-point drift. Additionally, inspect the sensing diaphragm for sediment or biological growth buildup and clean it carefully using a soft brush or liquid solvent, avoiding sharp tools that could scratch or damage delicate ceramic or metallic diaphragms.
Erratic or Fluctuating Output Signals
Unstable output readings or rapid signal jumps often indicate mechanical turbulence, electrical noise interference, or damaged wiring. Verify that the sensor probe is suspended away from direct fluid inlets, agitators, or pump outlets that generate dynamic pressure spikes; install a stilling pipe if necessary to stabilize the fluid column. Inspect signal cable shielding and intrinsic safety barrier earth connections to ensure proper equipotential grounding and prevent ground loop interference.
Complete Loss of Signal Output (0 mA / 4 mA Failure)
A complete drop in signal output typically stems from supply power failure, open circuit wiring, or barrier fuse trips within the hazardous area interface. Measure the supply voltage directly at the sensor terminals or barrier connections to verify adequate voltage under load. Inspect junction box connections for corrosion or water ingress, and test loop continuity across terminal blocks and zener barriers or galvanic isolators to locate any tripped safety components or broken conductors.
Slow Dynamic Response to Level Changes
A sluggish response to fluctuating fluid levels indicates partial obstruction of the pressure port or diaphragm cavity by thick sludge, slurry, or viscous residues. Remove the protective nosecone or filter cap if applicable, flush out trapped debris with clean water, and verify fluid viscosity remains within the operational specifications of the transmitter.