OEM Laser Rangefinder Module: Buyer's Guide
Buying an OEM laser rangefinder module is not like buying a finished product. You are buying a subsystem that must fit into your payload mechanically, electrically and optically, and be supported through qualification and production. The specification you write decides whether that works.
What "OEM module" means
An OEM module is a laser rangefinder or designator supplied as a component: no housing beyond the optical bench, no user interface, no display. It exposes a serial interface and a defined mechanical datum, and expects the integrator to provide mounting, power conditioning, cooling and command logic.
ERDI modules in the LDR and LR families follow this model: the host sends a ranging or designation command and receives range, status and self-test data over RS-422 or CAN.
The specification you should write
Optical
- Wavelength and pulse energy, with the target definition used for the range figure
- Beam divergence, stated as full-angle or half-angle, and the measurement convention
- Boresight requirement: angular alignment between the laser axis and your EO sensor axis, and stability over temperature
- Aperture envelope and window requirements
Electrical
- Supply voltage range and inrush behaviour. ERDI long-range modules specify 18–32 V DC typical 28 V, with defined average and peak consumption and inrush current limit
- Interface: RS-422 or CAN, with the message set and timing
- Isolation: digital ground, power ground and mechanical housing must be electrically isolated
- Emission control: hardware interlocks and software interlocks, and how the host asserts them
Mechanical and thermal
- Mass and centre of gravity
- Mounting datum, hole pattern and flatness
- Thermal path — where the heat goes, and the maximum base-plate temperature
- Duty cycle, stated as on-time and interval per mode
Environmental
- Operating and storage temperature
- Vibration and shock per a named standard. ERDI specifies vibration from 15 Hz to 33 Hz at 0.91 mm constant displacement and 33 Hz to 700 Hz at 2 g constant acceleration, one hour per axis in three orthogonal directions, with post-test operation required
- Shock: 10 g on each axis, post-peak sawtooth waveform, 11 ms duration, 18 shocks total
- Conformal coating for moisture and contamination protection
Datasheet traps
- Range without a target definition. "10 km" means nothing without stating the target reflectance, size and atmospheric visibility.
- Divergence convention unstated. Full-angle and half-angle differ by 2×.
- Accuracy convention unstated. 1σ, RMS or maximum error bound produce very different guarantees.
- Duty cycle omitted. A designator that runs 16 s on / 9 s off is a different product from one that runs continuously.
- Coding accuracy described as "typical". For designation, ask for the bound.
- Environmental standard named but not applied. "Designed to MIL-STD-810" is not the same as "tested and passed to a defined method".
Questions that reveal a real supplier
- Can you provide the controlled model datasheet with the parameter definitions?
- What is the measured, not design, divergence over temperature?
- What is the boresight stability over the operating temperature range?
- Which codes are supported and can they be changed in the field?
- What is the qualification status, and against which test methods?
- What is the production lead time and the configuration control process?
Integration checklist
| Stage | What to verify |
|---|---|
| Mechanical fit | Datum surface flatness, hole pattern, fastener torque, window clearance |
| Electrical | Inrush with your power supply, isolation, interface timing under load |
| Optical | Boresight to your EO sensor at both temperature extremes |
| Thermal | Base-plate temperature at the qualified duty cycle in your enclosure |
| Software | Command latency, error handling on dropped responses, self-test semantics |
| Flight / field | Range performance against real targets in real weather, not just the datasheet case |
Frequently asked questions
What is the difference between an OEM module and a finished rangefinder?
An OEM module is a component with a serial interface and a mechanical datum; a finished device adds housing, optics, display, battery and user interface. OEM modules are cheaper per unit and integrate into your payload; finished devices are used directly.
Do I need custom firmware?
Usually not, but you will need the message specification early so your host software can be written in parallel with hardware integration.
What is a typical minimum order quantity?
This is commercial and varies by model and configuration. Ask early, because it affects whether a module is viable for a prototype programme.
Can the module be branded for our product?
Mechanical branding and labelling are typically configurable; discuss with the supplier before tooling is cut.
Browse the 1064 nm module line-up, or read how to choose a laser rangefinder module.