In industries that store and process bulk solids, reliable level control is essential for preventing overflow, avoiding empty-bin conditions, protecting equipment and maintaining process continuity. Materials such as plastic granules, flour, cement, sand, coal, grain, powder sugar, milk powder, wood fibers and chemical raw materials require level switches that can operate safely under demanding conditions.
The DX-ELF Motorized Rotary Level Switch is designed for level control in silos and tanks where solid particulate materials are stored. With different probe, rod and paddle options, adjustable torque and strong mechanical construction, DX-ELF provides dependable full and empty level detection in a wide range of industrial applications.
What Is DX-ELF?
DX-ELF is a motorized rotary level switch used to detect the presence or absence of bulk solid materials inside tanks and silos. It can be mounted horizontally or vertically and provides reliable level information by using a rotating paddle mechanism.
The product family includes several model options, including DX-ELF 101, DX-ELF 102, DX-ELF 103, DX-ELF 103p, DX-ELF 104, DX-ELF 105, DX-ELF 106, DX-ELF 106m, DX-ELF 108 and DX-ELF 109. This wide model range allows users to select the most suitable design according to material type, silo geometry, mounting position and process temperature.
Operating Principle
DX-ELF works with a motor-driven rotating paddle. The switch is mounted on the tank wall, and a paddle selected according to the material is installed at the end of the probe.
When the area around the paddle is empty, the motor rotates the paddle continuously at the defined rotation speed. When the material level reaches the paddle and surrounds it, the material creates resistance against the rotating force.
At this point, the alarm contact is activated first. Then a second contact stops the motor. When the material level falls and the resistance on the paddle disappears, the motor starts rotating again and the alarm position changes.
This simple and robust principle makes DX-ELF suitable for full detection, empty detection and intermediate level monitoring in bulk solid applications.
Adjustable Torque for Different Bulk Densities
One of the key advantages of DX-ELF is its adjustable torque mechanism. The torque spring can be adjusted in four different stages according to the specific gravity and flow behavior of the material.
For materials with higher bulk density, the torque setting can be increased until reliable operation is achieved. For dry and low-density materials, a lower torque setting is preferred. For moist or sticky materials, a higher torque setting may be used to prevent false switching and improve detection stability.
This adjustable structure allows the same product family to be adapted to many different process materials.
Application Areas
DX-ELF can be used in a wide range of industries. In the plastic industry, it is suitable for materials such as PVC, PVDF and PP granules.
In the food industry, it can be used for grain, flour, salt, powder sugar, coffee, barley, sunflower seed, corn, peanut, powder materials, wheat, dried pepper, kaolin, milk powder and cocoa.
In the construction and mining industries, DX-ELF is suitable for lime, sand, calcite, mineral ore, cement, coal, gypsum, silica sand, calcium powder, limestone powder, crushed limestone, iron chips, styrofoam and molding sand.
It can also be used in wood industry applications such as sawdust filters and wood fibers, as well as chemical industry applications such as pharmaceutical raw materials.
Technical Specifications
DX-ELF has a standard process temperature range from -20 °C to +90 °C. Plastic connection models are suitable for -20 °C to +60 °C. With high-temperature model options, operation up to 150 °C or 200 °C is possible depending on configuration.
The operating pressure range is -0.6 bar to +0.6 bar. Ambient temperature is -20 °C to +60 °C, and ambient humidity is 0–98% RH, non-condensing.
The standard housing is aluminum injection AlSi12Fe, with black RAL 9005 finish. Standard paddle and rod material is 304 stainless steel, with 316 stainless steel available as an option. Connection material is aluminum as standard, with optional 304 or 316 stainless steel.
The protection class is IP66/IP68 according to EN60529.
Electrical and Switching Features
DX-ELF can be supplied with 24 VDC ±10%, 24 VAC, 48 VAC, 110 VAC or 220 VAC 50/60 Hz ±10% power supply options.
Power consumption is maximum 4 W for 220 VAC versions and maximum 3 W for 24 VDC versions. The standard rotation speed is 5 rpm in clockwise direction when viewed from the paddle side. Optional rotation speeds of 1.5 rpm and 1.8 rpm are available.
The relay switching capacity is 10 A / 250 VAC and 4 A / 30 VDC, with 2 x NO/NC SPDT contact structure. The device includes a green power LED and a red alarm LED for clear status indication.
Robust Mechanical Design
DX-ELF is designed for demanding bulk solid applications. It has strong mechanical resistance and a maximum load capacity of 500 N on the probe when using an extension pipe.
The maximum particle size is 50 mm, and the minimum density can be as low as 0.04 g/cm³, depending on paddle type. This makes the device suitable for both light and heavy bulk solids when the correct paddle and torque setting are selected.
The device also includes reverse rotation safety, supporting reliable operation and protecting the mechanical system.
ATEX-Certified Versions for Hazardous Areas
DX-ELF is available with ATEX-certified versions for explosive gas and dust atmospheres. The catalog lists certifications for gas and dust protection, including II 2G Ex db IIC Tx Gb, II 1/2G Ex h IIC Tx Ga/Gb, II 2D Ex tb IIIC Tx Db and II 1/2D Ex h IIIC Tx Da/Db.
This makes DX-ELF suitable for hazardous area applications where combustible dust or explosive atmospheres may be present, provided the correct certified model and installation conditions are selected.
Modular Structure and Easy Maintenance
The DX-ELF catalog shows a modular structure consisting of body mechanics, motor mechanics and paddle mechanics. This modular design supports flexible configuration, easier maintenance and adaptation to different silo or tank applications.
The housing includes clearly defined parts such as cover, body, product label, metal label, grounding terminal, cable gland, plug, connection fitting, rod and paddle. For ATEX-certified products, if the product label is damaged, the serial number on the metal label can be used to contact the manufacturer.
Model Options
DX-ELF offers different model configurations for various installation and process needs.
Models such as DX-ELF 101, 102 and 104 are suitable for horizontal or vertical mounting with standard paddle configurations. DX-ELF 103 is designed for vertical mounting with longer rod options. DX-ELF 103p is designed for EPS-XPS applications. DX-ELF 105 provides extended rod structure for deeper measurement points.
High-temperature configurations include DX-ELF 106 and DX-ELF 106m, with options up to 150 °C or 200 °C. DX-ELF 108 and DX-ELF 109 offer rope-type configurations for vertical mounting, with lengths up to 2 meters or 10 meters depending on model.
Paddle Options for Different Materials
DX-ELF can be configured with several paddle types. Options include standard sword paddle, mini sword paddle, spring folding paddle, spring folding Plexiglass paddle, cross-wing paddle and single-wing paddle designs.
Paddle materials include 304 stainless steel, 316 stainless steel and Plexiglass depending on the option. The correct paddle selection is important for reliable measurement, especially when handling low-density powders, sticky materials, granules or coarse bulk solids.
The catalog also includes example material densities for products such as sawdust, tea leaves, wheat flour, cement powder, silica sand, polypropylene, roasted coffee, coal, grain, sugar granules, wheat, PVC powder, PVC granules and red pepper.
Installation Considerations
Correct installation is critical for reliable operation. DX-ELF should be positioned according to the material flow and paddle type. The catalog shows recommended and non-recommended mounting positions.
The device should not be installed directly at the material inlet, in corners, near the outlet, or in positions where the paddle may be exposed to excessive mechanical load. For long rods, protective tubes or internal protection accessories may be required depending on silo geometry and material behavior.
Accessories and Configuration Options
DX-ELF can be supplied with various accessories, including reductions, sockets, flanges, protection plates, external protection covers, M12 5-pin socket, external LED fitting and cover-body chain.
The external protection cover is made from 304 stainless steel and is designed to protect the switch against external environmental conditions. It is welded, hinged and openable/closable for practical field use.
The ordering structure allows selection of model, certificate, rod type, immersion length, paddle type, connection, connection material, power supply, rotation speed, dust seal material, bearing type, housing material, electrical connection and optional accessories.
Why Choose DX-ELF?
DX-ELF is a strong choice for bulk solid level control because it combines simple operating principle with robust mechanical design and configuration flexibility.
Its advantages include fast delivery time, reverse rotation safety, adjustable sensitivity, excellent mechanical durability, different paddle options and the ability to operate in horizontal or vertical mounting positions.
For industrial plants handling powders, granules and particulate materials, DX-ELF provides practical and reliable full or empty detection in silo and tank applications.
Conclusion
The DX-ELF Motorized Rotary Level Switch is a robust and flexible solution for level control in silos and tanks containing solid particulate materials. With adjustable torque, multiple paddle and rod options, strong mechanical resistance, ATEX-certified versions and IP66/IP68 protection, it is suitable for demanding industrial bulk solid applications.
From food and plastics to construction materials, wood processing, chemicals and mining, DX-ELF helps operators monitor material levels reliably, prevent overflow or empty-bin conditions and improve process safety.