SITRANS LUT400 7ML5050-0AA12-1DA0 7ML5 050-0AA12-1DA0 7ML5O5O-OAA12-1DAO 7ML50500AA121DA0

7ML5050-0AA12-1DA0 | SITRANS LUT420 Ultrasonic Level Controller — Solids / Liquids / Slurries / Data Logging / 100–230VAC / 3×M20 / IP66/67

One Controller for Three Different Media Types, Up to 60 Metres

Most ultrasonic level controllers are optimised for either liquid or solid measurement. The SITRANS LUT420 handles both — and extends its application to slurries, with a non-contact measurement range reaching up to 60m (197 ft). This range covers everything from shallow collection tanks to tall bulk solid silos.

The LUT420 is currently in PM490 lifecycle status — its final year of manufacturer support. For installations that depend on this product, securing a replacement or spare unit now is advisable before end-of-life stock is depleted.

For liquids, the LUT420 measures the distance from the transducer face to the liquid surface and calculates level, volume, or flow depending on the configured vessel geometry. The non-contact ultrasonic measurement means no moving parts contact the liquid — suitable for aggressive chemicals, high-viscosity fluids, and liquids that would foul or damage mechanical sensors.

For bulk solids — grain, aggregate, cement, coal, pellets — ultrasonic level controllers face the challenge of irregular surfaces and angled material piles. The LUT420 applies averaging and echo processing algorithms that account for the cone-shaped surface profile typical of bulk solids storage, reporting a representative average level rather than a single point reading that can be unrepresentative of the actual inventory.

For slurries, the non-contact measurement eliminates the need for submerged sensors that require frequent cleaning or replacement in abrasive or sticky media.

Key Specifications

3 Relay Outputs + 2 Discrete Inputs — Integrated Process Control

The three relay outputs handle the standard level control functions from one controller: high-level alarm, pump-on setpoint, and low-level alarm can each be assigned to a dedicated relay without requiring an external controller or PLC for basic level control. Two discrete inputs accept external signals — remote reset, mode switching, or other control inputs — completing a self-contained level control loop in many pump and valve applications.

Application Scenarios

Bulk solid silo management: Cement silo with sloped material pile. The LUT420's averaging algorithms calculate representative fill level despite the conical surface. Built-in logging records daily consumption for production planning.

Chemical liquid storage: Acid or solvent tank where direct contact sensors require chemical compatibility and frequent replacement. Ultrasonic non-contact measurement provides continuous level without chemical exposure to the sensor electronics.

Wastewater and slurry basins: Settling or equalisation basins with variable consistency media. The LUT420's slurry capability provides continuous level indication where contact sensors would require frequent maintenance.

Multi-vessel inventory control: The LUT420's multi-point relay output capability controls pumps or valves based on level thresholds — high-level alarm, pump-on setpoint, low-level alarm — from one instrument.

FAQ

Q1: What transducer is compatible with the 7ML5050-0AA12-1DA0?

The SITRANS LUT420 is used with SITRANS Probe LU or compatible ultrasonic transducers from the SITRANS ultrasonic product family. The transducer selection depends on the measurement range required (near range for shallow tanks, extended range for tall silos), the beam angle appropriate for the vessel diameter, and whether PTFE or other special material construction is needed for the specific media. Confirm the transducer compatibility from the SITRANS LUT420 device manual and the Ultrasonic transducer selection guide.

Q2: What communication outputs does the LUT420 provide?

The SITRANS LUT420 supports HART protocol (superimposed on the 4–20mA loop) for digital data access alongside the analogue output, and RS-485 (Modbus) for direct integration with DCS or SCADA systems that support serial communication. Relay outputs provide switch signals for pump control, valve control, and alarm annunciation at configurable level setpoints.

Q3: How does the built-in data logging retrieve its stored records?

Data log records are accessible locally via the instrument's display interface and menu navigation. Remote access is via the HART communication port using a HART handheld communicator or HART-enabled DCS/asset management system. The log capacity and retrieval method are detailed in the SITRANS LUT420 user manual under the data logging configuration section.

Q4: What is the IP66/IP67 rating's significance for field installation?

IP66 indicates the enclosure is protected against powerful water jets (6 = protected against strong water jets from any direction). IP67 adds protection against temporary immersion in water up to 1m depth. Both ratings together cover harsh outdoor field installations — rain, washdown, and temporary flooding conditions — without requiring additional protective housings in most standard industrial environments.

Q5: How is the 7ML5050-0AA12-1DA0 programmed and configured?

Configuration uses the SITRANS LUT420's local keypad (four-button programming interface) and the onboard LCD display for parameter entry — vessel geometry, measurement range, alarm setpoints, relay assignments, and data logging intervals. Remote configuration and calibration are available via a HART handheld communicator or PC-based SIMATIC PDM (Process Device Manager) software connected via the HART interface.