| Measuring range | 50 – 300 mm |
|---|---|
| Accuracy | ±0.5 % FS |
| Repeatability | ±5 µm |
| Output signal | 4 – 20 mA / 2 × PNP |
| Supply voltage | 12 – 28 V DC |
| Process connection | M12 × 1 connector |
| Enclosure protection | IP67 IEC 60529 |
| Operating temperature | 0 – 45 °C |
Does ambient light affect a triangulation laser?
Modern sensors modulate the laser and tune the receiver to that modulation, so daylight and lamps mostly consume signal margin as noise rather than adding bias, though strong reflections from neighbouring parts still eat that margin.
Why specify repeatability as well as accuracy?
Accuracy says how close readings sit to the true value after calibration, while repeatability says how tightly repeated measurements agree with each other, and a station that checks the same gap over and over lives or dies by the second number.
What matters when replacing a sensor at a station?
Keeping the range, the response mode and the mounting geometry preserves the meaning of the old calibration, whereas a new model with the same output signal but different optics will read a different number on the very same part.
Definition
A laser displacement sensor derives the position of a surface from where the reflected laser spot is imaged on an internal detector, using emitter-receiver geometry.
On an assembly line the ALD-350 answers small questions fast, whether a part sits flush or how wide a gap is, at distances of tens of millimetres where slower ranging methods give away resolution.
Triangulation geometry and why range costs resolution
A laser diode projects a small spot onto the target, and the receiver optic images that spot onto a position-sensitive detector held at a fixed baseline and angle. When the surface moves, the image slides along the detector, and the slide is converted into a distance through the calibration of that geometry. A short baseline with a sharp optic turns tiny movements into large detector travel, which is why the near range is where the fine resolution lives. Push the same principle to metres and the image travel per micron collapses, so range is bought by giving resolution up.
Working around shiny and dark targets
Specular panels, bare aluminium and matte black sealants each fight the triangulation receiver in a different way, one throwing the specular glare past the detector, the other returning too little energy to locate a spot. Housing angle, an adjustable exposure time and the choice between diffuse and specular response modes are the field tools for this, and the mount has to hold the angle the mode was chosen for. After a material or colour change at the station, the signal margin should be re-checked and the new mode and angle recorded with the fixture drawing.
Mounting and the line controller it reports to
Bracket stiffness matters more than most settings, because a bracket ringing near the frequency of the machine blurs the spot and invents motion the part never had. The current output or the switching outputs then carry a verdict into the line controller, where the useful question becomes how fast the sensor must repeat compared with the station cycle. Bracket resonance is why short cable runs and solid mounts beat clever tuning every time. Where several sensors sit side by side, stagger their moments or modulate their light so neighbouring spots do not cross-talk, and keep signal cable away from power cable.
All figures on this page are illustrative sample values, not measured specifications.