Product overview
The Siemens SITRANS LR120 is a compact, non-contact radar transmitter for continuous level measurement of liquids, slurries and bulk solids over distances up to 30 metres.
Its narrow radar beam makes it especially suitable for tall tanks, wet wells, silos and vessels containing internal structures or other obstructions.
Key features
- 80 GHz FMCW radar technology
- Non-contact continuous measurement
- Measuring range up to 30 metres
- Approximately ±2 mm accuracy
- Very narrow 4° radar beam
- Zero near-range or blocking distance
- Bluetooth setup through SITRANS Mobile IQ
- Chemically resistant PVDF enclosure
- Suitable for liquids, slurries and solids
- Optional submergence shield
- Hazardous-area versions available
- No moving parts and minimal maintenance
- Suitable for open-air measurement
Technical specifications
| Parameter | Specification |
|---|---|
| Measuring principle | 80 GHz W-band FMCW radar |
| Measuring range | 0–30 m |
| Accuracy | ±2 mm from 0.25–30 m |
| Beam angle | Approximately 4° |
| Output | 4–20 mA |
| Communication | HART 7 or optional Modbus RTU |
| HART power supply | 12–35 V DC |
| Modbus power supply | 8–30 V DC |
| Process pressure | −1 to +3 bar |
| Process temperature | −40°C to +80°C |
| Ambient temperature | −40°C to +80°C |
| Housing material | PVDF |
| Protection rating | IP66/IP68 |
| Cable lengths | 5, 10, 30, 50 or 100 metres |
| Configuration | Bluetooth, SIMATIC PDM or DTM |
| Hazardous-area approvals | ATEX, IECEx and other regional options |
Marine approvals
Marine-approved configurations are listed for:
- ABS
- CCS
- DNV
- Lloyd’s Register
- ClassNK
- RINA
Current certificate validity and the required classification approval should be confirmed when ordering.
Marine and industrial applications
- Ballast and freshwater tanks
- Sludge and wastewater tanks
- Deep marine storage tanks
- Bilge wells and pump wells
- Offshore process vessels
- Chemical-storage tanks
- Cargo and bulk-material silos
- Cement and aggregate storage
- Plastic-pellet silos
- Water-treatment facilities

