External mounted level sensors for installing on the outside of a liquid storage tank to measure level of tank contents. These level sensors have a screw-in, clamp or bolt-on flange fitting to attach the sensor to a connection port on the external wall of the tank.
External mounted tank level sensors provide a versatile and robust solution for measuring liquid levels by attaching to connection ports on the tank’s exterior, such as screw-in, clamp, or bolt-on flange fittings. This design is particularly beneficial for applications involving corrosive, sterile, or difficult-to-access media, as it isolates the sensor from the tank contents, facilitating easier maintenance and enhancing sensor lifespan, making them a preferred choice for design engineers and instrument technicians in chemical, pharmaceutical, and water treatment industries.
LMK351 High Overpressure Flush Level Transmitter - Flush capacitive ceramic pressure sensor for measuring corrosive and viscous liquid level from levels 0.4 metres of water up to 200 mH2O. 
LMK331 Screw-In Ceramic Level Transmitter - Level pressure sensor with semi-flush ceramic diaphragm and stainless steel or PVDF wetted parts in ranges from 0-4 to 600mH2O gauge.
DPT200 Pressurised Tank Level Differential Pressure Transmitter - Pressurised tank liquid level differential pressure cell transmitter for process plant storage.
DMP331P Hygienic Flush Pressure Transmitter - Sanitary pressure sensor wth exposed diaphragm with no crevices for high temperatures up to 300 Degrees Celsius in ranges from 100mb up to 40 bar gauge or absolute
DS200 Combined Hydrostatic Level Switch, Gauge and Sensor - Three in one hydrostatic level switch, digital level gauge and level sensor with level ranges from 1 mWG up to 600 mWG (3.3 to 1969 ftWG).
DMK 458 Seawater Low Range Pressure Transmitter - Sea water corrosion resistant low range pressure transmitter for marine, ship and offshore engineering.
Find out more about External Mounted Tank Level Sensors to determine which product options and capabilities will best meet your application requirements.
External mounted tank level sensors are designed for robust liquid level measurement where the main body of the sensor is installed on the outside of a storage tank, while its sensing element interfaces directly with the tank’s contents through a dedicated connection port. This configuration means that while the wetted parts of the sensor, such as a diaphragm, probe, or float mechanism, are exposed to the process media, the primary electronics, housing, and process connection interface remain external to the tank’s internal environment. This design is particularly advantageous as it protects the bulk of the instrumentation from harsh internal tank conditions such as extreme temperatures, corrosive vapors (beyond the immediate wetted area), or physical interference from mixers or agitators. Crucially, it allows for easier access to the sensor’s main housing for setup, diagnostics, or replacement without requiring entry into the tank, although process isolation at the connection port is typically necessary for maintenance. The integrity of the seal at the tank wall penetration and the material compatibility of the wetted components with the liquid are paramount design considerations for engineers and technicians working with these instruments.
The connection to the tank is typically achieved through robust mechanical interfaces such as screw-in threaded fittings, versatile clamp-on assemblies, or secure bolt-on flange arrangements. Screw-in types, often utilizing NPT or BSP threads, are common for smaller tanks or where a simple, direct port is available. Clamp fittings, such as Tri-Clamp or similar sanitary connections, are frequently specified in hygienic applications like food, beverage, and pharmaceutical processing, where ease of cleaning and prevention of contamination are paramount. For larger tanks, or in systems operating under higher pressures or temperatures, bolt-on flanges conforming to ANSI, DIN, or JIS standards provide a highly secure and leak-proof connection, crucial for safety and environmental compliance in chemical plants or refineries.
Instrument technicians and design engineers should consider the specific design of the connection port, ensuring material compatibility between the sensor fitting, the port, and the process environment to prevent galvanic corrosion or chemical degradation. The choice of mounting also influences the type of sealing mechanism employed, ranging from O-rings and gaskets for threaded and clamped connections to specialized flange gaskets for high-integrity seals. These externally mounted sensors are commonly employed in a diverse range of industries, including chemical storage facilities monitoring aggressive reagents, water treatment plants for bulk water or effluent levels, and in manufacturing processes where tanks may contain viscous liquids or slurries not suitable for internal probes. Their application is also valuable in retrofitting level measurement capabilities to existing tanks where internal modifications are complex or cost-prohibitive, allowing for upgraded process monitoring with minimal structural alteration.