Frequently asked
questions

Yes. ERDI's 905 nm module lines are Class 1 eye-safe under IEC 60825-1, meaning they are safe under all reasonably foreseeable conditions of use — no viewing restriction and no protective eyewear needed. You can align, demonstrate and operate the device around people, which is exactly why 905 nm suits night-vision, thermal and security products.

905 nm uses low-cost silicon detectors and stays Class 1 eye-safe, which makes it the compact, cost-effective choice for sub-3 km ranging in night vision, thermal and UAV integration — that is the entire scope of this site. Step up to 1535 nm when you need longer range with a larger eye-safe margin, or 1064 nm for designator-class work. For those wavelengths and light sources, see the ERDI global site (erdicn.com).

DToF (direct time-of-flight) times how long a laser pulse takes to travel to the target and back, then converts that directly into distance — the same principle behind every module on this site. It scales cleanly to hundreds or thousands of metres, unlike triangulation (accurate only at short range, sensitive to baseline geometry) or continuous-wave phase ranging (fast and precise at short range but ambiguous beyond one wavelength cycle without extra unwrapping logic). DToF is why a 6 g module can still reach 1,200 m.

Maximum range is quoted against a reference target — for the flagship, ≥ 3,000 m on a 70% reflectivity building under clear conditions (visibility ≥ 4 km). Real reach depends on target reflectivity, size and weather: a low-reflectivity or small target reads shorter, and many modules reach further at night than by day. Minimum range (e.g. 0.2–1 m) is the closest distance the module will still measure. Always design to the reference conditions on the spec sheet and validate against your own target.

Accuracy is specified per model and typically tightens at close range: the flagship holds ±0.7 m to 100 m, then adds a small distance-proportional term beyond that. The SPD mini series reaches ±0.3 m to 100 m; the tube and adaptive series are around ±1 m. Each spec sheet gives the exact accuracy formula by distance band — use those figures, not a single headline number.

The standard interface is UART-TTL at 3.3 V logic, 115200 bps by default (9600 bps optional on several models), over a 6-pin connector. Supply is DC 3.3–5 V. The interface and baud rate are customizable for OEM integration. See each model's spec sheet for the exact pinout.

Measurement frequency is how often the module reports a new distance once it is running — typically an adaptive 2–20 Hz band depending on model, so the module can trade update rate for range as the scene changes. Response time is separate: it covers power-on/start-up plus the first measurement, which can add on the order of a few hundred milliseconds before the first reading is available. Design your host polling loop around the sustained frequency, and budget for the response time only at power-up.

A missed reading usually means the return signal fell below detection threshold — low target reflectivity, rain, fog, dust or an off-axis target. Every module is specified with a valid measurement rate (typically ≥ 98% under reference conditions) and a false alarm rate (typically ≤ 1%), and firmware rejects returns that don't match a plausible signal profile. For unreliable surfaces, average multiple readings in your host logic rather than trusting a single sample.

Start from weight and reach, in that order. SPD mini (≈5–10 g) is for SWaP-critical clip-ons and micro-UAVs; E-adaptive (≤10 g) trades a bit of size for graded precision at 1,000–2,000 m; D-class1 (Ø23 mm tube, ~20 g) adds IP67 lens sealing for outdoor/industrial duty; B-tube is the cost-efficient cylindrical core for monoculars and telescopes; and the flagship LRF3000A1 is the long-reach choice at 12 g when you need past 3,000 m. The comparison table on /products/ sorts all of this by range, accuracy and weight in one view.

The SPD mini series is built for this: SPD1200M2 (6 g, 7.7 × 15.3 × 27.85 mm) and SPD1200N0 (5 g, Ø15.7 × 21.3 mm) both range 0.2–1,200 m (1,500 m at night) at ±0.3 m near range — light enough to add a distance readout without pushing the device out of its weight or eye-safety budget.

For altitude hold and target cueing on a stabilized payload, the flagship LRF3000A1 gives the longest reach at the lowest weight (12 g, ≥3,000 m). If the platform also needs attitude data alongside distance, SPD1200S2G adds an integrated gyroscope so range and orientation arrive from one module.

Every module on this site is Class 1 under IEC 60825-1 by design — that eye-safety ceiling, not raw laser power, is what lets these modules run near people and pass through civil/commercial channels without the handling restrictions that Class 3B/4 designators carry. If your application genuinely needs designator-class output and range, that is outside this site's 905 nm scope — see the ERDI global site.

Always compare like for like: check whether the quoted range is against a building/board target or a lower-reflectivity target, and whether a night-time figure is called out separately. Each model's own spec sheet states its reference target and visibility condition — the comparison table gives the headline numbers, but for a tight fit, open the model page and read the qualifying conditions, not just the top-line metre figure.

Yes — every module here is a single 905 nm engine that ranges in daylight and darkness alike; several (the SPD mini and E-adaptive series in particular) publish a longer night-time maximum range than their daytime figure, since ambient light competes less with the return signal after dark. No day/night mode switch is needed.

SPD1200N0 is the lightest at ≈5 g in a Ø15.7 × 21.3 mm body. The trade-off against the flagship is reach and beam quality, not eye-safety or build quality: it ranges to 1,200 m (1,500 m at night) versus the flagship's 3,000+ m, in exchange for roughly a fifth of the weight.

ISO 9001:2015 quality management, CE, RoHS, FDA laser-product compliance, IEC 60825-1 Class 1 eye-safety, and MIL-STD-810G shock/vibration testing. Not every certification applies to every model in the same way — see the /quality/ page for what each one means for your build, or ask us to confirm coverage for a specific model.

Yes. Every module is calibrated automatically for output power and wavelength, then verified against its own published specification before leaving the line — nothing ships untested.

In-house. Design, CNC machining, clean optical assembly and automated calibration all happen under one roof in Chengdu, with more than 15% of annual revenue reinvested in R&D. That vertical integration is what lets a 12 g module hold a specified ±0.7 m accuracy batch after batch.

Application definition (target, range, update rate, acceptance criteria) → optical link budget (transmitter, beam, aperture, noise margin) → electronics and firmware (power, timing, receiver chain, fault behaviour) → optomechanical packaging (datums, boresight, thermal path, connector) → prototype verification (measured behaviour against the controlled spec) → design transfer and revision (build controls, release record, managed updates). See /about/ for the full breakdown.

Modules are qualified to MIL-STD-810G shock and vibration methods (typically rated to 1000 g/ms shock, 5–50–5 Hz vibration at 2.5 g on most models), with IP67-sealed lens cavities on the majority of the line and an operating range of -20 to +60 °C standard (a -40 °C low-temperature build is available on several series). Exact limits vary by model — check the individual spec sheet.

Yes, on request. Because every unit is calibrated and tested against its published spec before shipping, we can supply per-unit test data or the relevant certificate (ISO/CE/RoHS/FDA) alongside your order — useful if your own incoming-quality process needs evidence beyond the datasheet. Ask for it with your RFQ.

Modules across the line are designed to a reliability target of MTBF ≥ 1,500 hours, alongside a typical valid measurement rate of ≥ 98% and a false alarm rate of ≤ 1% under reference conditions. Exact figures are on each model's own spec sheet.

MOQ depends on the model and whether any customization is involved. Samples are available in small quantities for evaluation, and production MOQs are typically modest for standard modules. Tell us the model and your expected volume in an RFQ and we'll confirm the exact MOQ for your case.

Standard samples typically ship within about a week of order confirmation; custom or modified modules depend on design complexity. Sample pricing is quoted per model on request. Send an RFQ with the model and quantity and we'll come back with cost and lead time, usually within one business day.

Yes. As the manufacturer we customize the mechanical envelope, optical configuration, interface and baud, driver electronics, firmware behaviour, logo engraving and packaging — from a modified standard module through to a design built to your specification, with a clear sample-to-production path.

Yes — UART-TTL baud rate (115200 bps default, 9600 bps and others available), the output data frame, continuous versus triggered measurement mode, and function-enable behaviour can all be adapted to match your host firmware. Tell us your existing protocol if you need the module to drop straight in.

Yes. Housing shape, mounting points, window/lens geometry and connector type can be modified from a standard model, or designed from the envelope out for a clean-sheet build. This is where the six-stage development process (application definition → optomechanical packaging → prototype verification) applies most directly.

Yes — laser-engraved branding and custom packaging are available for finished OEM products, alongside the mechanical and firmware customization above.

Target platform and use case, required range and accuracy, interface and baud rate, mechanical envelope or weight limit, operating environment (temperature, sealing), and expected annual volume. The engineering-requirements section of the quote form on this site captures exactly these fields — fill in what you know and leave the rest for us to ask.

Send a quote request (RFQ) with the model or your requirements — target platform, range and accuracy, interface and expected annual volume. We reply with the right module, unit pricing and lead time, typically within one business day. Prices shown anywhere on this site are indicative volume starting points, not a quote.

Yes. ERDI ships worldwide with export documentation, and holds CE, RoHS and FDA compliance for the major markets, plus regional offices in the USA, Canada, Japan, Singapore and Taipei. Because the 905 nm rangefinder line is Class 1 eye-safe (not a designator), it avoids the tightest export categories — confirm the specifics for your destination with your RFQ.

Every module carries a 2-year warranty; within the first 12 months any verified manufacturing defect is replaced with a new unit free of charge. A 30-day trial and return window applies from delivery, and technical support is available for the lifetime of the product — direct from the engineers who build the modules.

Contact us with the model, serial/order reference and a description of the fault. Within the first 12 months, any verified manufacturing defect is replaced with a new unit free of charge under the 2-year warranty; outside that window, we still provide lifetime technical support and will quote a repair or replacement path.

Samples ship with the model's datasheet (also downloadable free from /resources/); a Windows configuration tool and the full command set (continuous mode, frequency, baud, address) are provided alongside samples, and a full integration manual is available on request for a specific model.

Yes. The UART-TTL wiring and command-frame basics common to the whole line are on /resources/; the complete integration manual, command reference and a Windows configuration tool ship with your samples, or on request ahead of a sample order if you need to plan integration first.

The same team that designs and builds the modules — support is not outsourced to a call center. Reach us through the quote form or by email and we'll route technical questions straight to engineering; lifetime technical support is part of every module's warranty.

Production lead time depends on the model, quantity and any customization, and shipping terms are agreed per order. Tell us your target quantity and destination in an RFQ and we'll confirm lead time and terms alongside the quote.