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Intrinsically Safe Liquid Level Sensors

Find robust intrinsically safe liquid level sensors for petrochemical, landfill & chemical applications. Submersible IP68 & external mount versions meeting ATEX/IECEx standards.

Intrinsically safe liquid level sensors provide essential measurement capabilities in hazardous areas where flammable gases or dust create an explosion risk. Engineered to limit electrical and thermal energy below ignition thresholds (ATEX/IECEx standards), these sensors are available for external tank mounting or as submersible probes for boreholes and sumps, often featuring high-integrity IP68 sealing. They are crucial for safely monitoring levels of water, fuels, chemicals, and contaminants in demanding applications within the petrochemical, chemical processing, environmental monitoring, and mining industries.

Find out more about Intrinsically Safe Liquid Level Sensors to determine which product options and capabilities will best meet your application requirements.

Intrinsically safe liquid level sensors are specifically engineered for deployment in environments where the potential for ignition exists due to the presence of flammable gases, vapors, or combustible dusts. These sensors operate on the principle of limiting electrical and thermal energy under both normal operation and fault conditions to levels insufficient to ignite the surrounding hazardous atmosphere, adhering to stringent intrinsic safety (IS) protection concepts. Compliance with standards such as ATEX, IECEx, or other regional certifications is paramount, ensuring the sensor design inherently prevents sparks or hot surfaces that could serve as an ignition source in classified hazardous locations like Zone 0, 1, or 2.

The implementation of intrinsic safety necessitates careful system design, involving not only the sensor itself but also its connection via certified IS barriers or isolators located in the safe area. These barriers regulate the energy transferred to the sensor in the hazardous zone. The sensors are designed with specific low-voltage and low-current characteristics, along with considerations for capacitance and inductance, to meet the strict energy limitations required for IS approval. This design constraint influences the types of sensing technologies feasible for IS applications and requires careful selection based on the measurement requirements and environmental conditions.  

For applications involving storage tanks containing volatile chemicals, fuels, or solvents within a potentially explosive atmosphere, externally mounted intrinsically safe level sensors provide a crucial measurement solution. These sensors are often designed for ease of installation on tank walls or via existing fittings, minimizing intrusion while providing continuous monitoring. Their IS certification ensures that the measurement process itself does not introduce an ignition risk to the potentially hazardous vapors present above the liquid surface or surrounding the tank installation.

Submersible intrinsically safe level sensors are essential for tasks such as monitoring groundwater levels in contaminated land remediation sites, tracking leachate accumulation within landfill boreholes, or gauging water levels in wells associated with petrochemical facilities or mining operations. The integrity of the cable and its termination is particularly critical in these applications. High-integrity, permanently sealed cable entries, achieving an IP68 rating, are vital not only for preventing liquid ingress and ensuring long-term measurement accuracy but also for maintaining the intrinsic safety protection over the sensor’s operational life, preventing faults that could compromise the energy limitations.

Material compatibility is a key consideration when selecting intrinsically safe level sensors, especially for submersible types or those measuring aggressive chemicals. Housings are typically constructed from robust materials like stainless steel (e.g., 316L) or specialized polymers chosen for their resistance to corrosion and chemical attack from substances ranging from hydrocarbons and solvents to acidic or alkaline solutions found in industrial process tanks or environmental monitoring wells. Ensuring the sensor’s materials can withstand the specific media without degradation is crucial for both measurement reliability and maintaining the physical integrity required for safe operation in hazardous zones.

These sensors are deployed across diverse industrial and environmental monitoring scenarios where safety is non-negotiable. Examples include level monitoring in chemical processing reactors, fuel storage depots, offshore platform service tanks, wastewater treatment digesters generating biogas, pharmaceutical manufacturing vessels, and environmental monitoring boreholes near petrol stations or industrial sites. The ability to reliably measure levels of water, oils, various chemicals, and even viscous media, while adhering to intrinsic safety standards, makes these sensors indispensable tools for process control, inventory management, and environmental protection in hazardous areas.