Key Technical Specifications
- Product Model: LM80
High-performance laser transmitter for industrial level measurement. - Manufacturer: ABB
Global leader in process automation and level instrumentation. - Measurement Principle: Pulsed Laser Time-of-Flight
Calculates distance based on light travel time for high precision. - Level Range: Up to 100 m (330 ft)
Suitable for mid-to-high range silos and bunkers. - Positioning Range: Up to 150 m (500 ft)
Extended range for crane positioning or long-distance targeting. - Target Media: Granular Solids & Opaque Liquids
Optimized for pellets, grains, salt, and non-transparent fluids. - Dust Tolerance: Light to Moderate Dust
Pulse detection handles typical industrial dust; heavy dust may require radar. - Beam Divergence: Negligible (No Beam Spread)
Eliminates false echoes from vessel walls or internal structures. - Aiming Aid: Integrated Visible Laser Pointer
Allows precise visual alignment in narrow or tall vessels. - Output Signal: 4–20 mA + Relay
Continuous level signal plus high/low alarm relays. - Housing: Aluminum (Stainless Steel Optional)
Rugged construction for harsh industrial environments. - Certifications: CSA, ATEX, IECEx
Approved for hazardous and explosive atmospheres.
Product Introduction
ABB LM80 is a mid-range laser level transmitter designed for non-contact measurement of granular solids and opaque liquids. It uses pulsed laser technology to deliver accurate level, distance, and positioning data in environments where ultrasonic or radar may struggle with internal obstructions.This module stands out with its negligible beam divergence, which prevents false echoes from support beams or vessel walls—a common failure point for radar in salt or pellet bins. The built-in visible laser pointer simplifies alignment in tall silos, while the 100m range covers most mid-sized storage applications. (I’ve seen ultrasonic fail completely when a bin hits 30% empty due to center peaks; the LM80’s narrow beam simply shoots past the peak to the true surface.)
Installation & Configuration Guide
Preparation (10 min)
Verify the vessel height and mounting location. Ensure the laser path is clear of obstructions like ladders, agitators, or fill streams. Check that the 24 VDC power supply is stable and within spec. Have the LCD2 hand programmer or configuration software ready.Removal (5–10 min)
If replacing an existing unit, isolate power and disconnect the 4–20 mA and relay wiring. Label all wires before disconnecting. Unscrew the LM80 from the flange or mounting bracket. Inspect the mounting surface for corrosion or damage; clean if necessary.Installation (10 min)
Mount the LM80 using the appropriate flange or bracket. Connect power and signal wires per the terminal diagram; verify polarity. Use the integrated visible laser pointer to aim the beam at the target surface, avoiding direct hits on vessel walls or fill streams. Tighten all connections to specified torque.Power-On & Test (10 min)
Apply 24 VDC power. The status LED should indicate normal operation. Use the LCD2 hand programmer to verify the measured distance matches a known reference (e.g., tape measure drop). Configure the 4–20 mA scaling and relay setpoints. Trigger a manual alarm test to verify relay operation.
Troubleshooting Quick Reference
| Symptom | Probable Cause | Immediate Check |
|---|---|---|
| No Signal / 4mA | Power or wiring fault | Measure 24 VDC at terminals; check fuse/breaker. |
| Erratic Readings | Dust interference or misalignment | Clean lens; verify aim with laser pointer; check for fill stream. |
| False High Level | Reflection from internal structure | Re-aim using laser pointer; avoid support beams and walls. |
| No Laser Pointer | Pointer disabled or failed | Check configuration setting; verify pointer LED operation. |
| Relay Not Triggering | Setpoint or wiring issue | Verify alarm setpoint in config; test relay output with meter. |
| Condensation on Lens | Temperature differential | Install optional heated lens; check housing seal integrity. |
Dimensions, Mounting & Wiring Notes
- Mounting: Flange, thread, or bracket mount; verify vessel opening size.
- Wiring: 4–20 mA and relay outputs via cable gland or M12 connector. Use shielded cable for signal lines; ground shield at controller end only.
- Lens Care: Clean with soft cloth and mild solvent if dusty. Optional heated lens available for condensation-prone environments.
- Safety: Never look directly into the laser beam. Class 1 laser product; safe under normal operating conditions.
FAQ
Can the LM80 measure through heavy dust?
It handles light to moderate dust well, but fine powders like salt or cement can create a dense cloud that scatters the laser. In those cases, I’d recommend guided wave radar instead. (I’ve seen salt bins where dust was so thick you couldn’t see 2 meters; the laser just bounced back off the dust layer.)Do I need to calibrate the LM80?
No. The LM80 is factory-calibrated and uses time-of-flight measurement, so no field calibration is required. You only need to configure the vessel height and 4–20 mA scaling.What’s the difference between LM80 and LM200?
The LM200 offers longer range (up to 250m) and better performance in extreme temperatures or heavy dust. If your silo is under 100m and dust is moderate, the LM80 is more cost-effective. For harsher conditions, go LM200.Can I use this for transparent liquids?
No. Laser level transmitters require an opaque surface for reflection. For clear water or solvents, use radar or ultrasonic. The LM80 is strictly for granular solids and opaque liquids.I’m getting false echoes from a support beam, help?
Re-aim using the built-in laser pointer to shoot between the beams. The LM80’s narrow beam divergence is specifically designed to avoid this. If you can’t find a clear path, consider relocating the mount or switching to guided wave radar.Is the laser pointer always on?
It can be configured to stay on continuously or activate only during setup. Continuous mode helps with visual verification but consumes slightly more power. Check the configuration menu to adjust.Does it work in explosive atmospheres?
Yes. The LM80 carries ATEX, IECEx, and CSA certifications for hazardous areas. Verify the specific certification marking matches your zone classification before installation.
