The problem: you need a bare serial laser rangefinder that reaches a ridge line, tower or building about 1.2 km away, and every distributor page quotes one big range number and nothing else. Here is the comparison I think that search deserves: a shortlist of modules that reach 1 km or more, with the numbers that actually decide the choice (range and the target it was measured on, accuracy at distance, update rate, supply, weight, price) and a small Python script that evaluates each maker's accuracy rule at the distance you care about.
All ERDI figures come from the product pages on erdilrf.com and the manuals behind them, checked on 2026-11-07. Benewake figures come from the public product comparison table at en.benewake.com, read the same day. I only list what the maker publishes, and I say where a number is missing. Treat everything as a shortlist, not a benchmark: makers measure on different targets in different weather.
Short answer
| If you need | Look at first | Why |
|---|---|---|
| Cheapest 1 km class, slow readings | ERDI LR1000E2 (USD 80) | 4-1,000 m, UART, about 10 g |
| 1.5-2 km on a small bare board | ERDI LR1500E2 / LR2000E2 (USD 100 / 120) | same serial protocol across the family |
| 3 km class | ERDI LRF3000A1 (USD 200) | 3,000 m or more on a 70 % reflectivity building |
| Faster readings at 1 km+ | Benewake TFA1500-L | 60-800 Hz adaptive, 0.5-1,500 m |
| Better close-in accuracy at 1.2 km | ERDI SPD1200S2 (USD 150) | ±0.3 m up to 400 m |
The comparison table
| Module | Maker's range figure | Accuracy | Rate | Interface / supply | Weight | Price shown |
|---|---|---|---|---|---|---|
| LR1000E2 | 4-1,000 m (standard range) | ±1 m to 400 m; ±(1 + 0.001 D) m beyond | not on page | UART-TTL, 3.3-5 V | 10 g or less | USD 80 |
| LR1200E2 | 4-1,200 m (standard range) | ±1 m (6-500 m); ±(0.5 m + 0.001 D) beyond | not on page | UART-TTL, 3.3-5 V | 10 g or less | USD 90 |
| LR1500E2 | 4-1,500 m (standard range) | same two-step rule as LR1200E2 | not on page | UART-TTL, 3.3-5 V | 10 g or less | USD 100 |
| LR2000E2 | 4-2,000 m (standard range) | ±1 m to 400 m; 0.4 % of distance to 2,000 m | 2-10 Hz adaptive | UART-TTL, 3.3-5 V | about 10 g | USD 120 |
| LRF3000A1 | 3,000 m or more (70 % reflectivity building, clear weather, visibility 4 km or more) | ±0.7 m to 100 m; ±(0.7 + 0.003 D) m beyond | not on page | UART 3.3 V TTL, 3.3-5 V | 12 ± 0.5 g | USD 200 |
| SPD1200S2 | 0.2-1,200 m catalogue range | ±0.3 m to 400 m; ±(0.5 m + 0.1 % D) to 1,200 m | 4-15 Hz adaptive | UART-TTL, 3.3-5 V | 10 g or less | USD 150 |
| LRF1500H | 0.05-1,500 m at 90 % reflectivity; 0.05-300 m at 10 % | not on page | 1 kHz or 50 Hz (automatic) | UART / I2C, 9-36 V | 20 ± 2 g | USD 400 |
| Benewake TFA1200-L | 3-1,200 m | not on comparison table | 3 Hz | UART | 11 g | not listed |
| Benewake TFA1500-L | 0.5-1,500 m | see its datasheet | 60-800 Hz adaptive | UART | 11 g | not listed |
Sources: the ERDI model pages linked above (checked 2026-11-07); the Benewake product comparison table at https://en.benewake.com/TF03/index.html (read 2026-11-07). ERDI prices are the published USD unit prices for 1 to 30 pieces, shipping included. Volume tiers are lower and are on each page.
What the table does not show at first glance
The accuracy rule decides the usable range. A flat "±1 m" would be easy to compare. These modules use a distance-dependent rule, and at the far end it dominates:
- LR2000E2 at 2,000 m: 0.4 % of distance is ±8 m.
- LRF3000A1 at 3,000 m: 0.7 + 0.003 × 3,000 = ±9.7 m.
- SPD1200S2 at 1,200 m: 0.5 + 0.001 × 1,200 = ±1.7 m.
That is fine for "is there a structure there, and roughly how far", and not enough for surveying. If you need sub-metre accuracy at several hundred metres, the SPD family's ±0.3 m up to 400 m is the better starting point. If you need reach over accuracy, the 3 km part wins.
"Standard range" is a best case. The E2 pages say outright that actual reach depends on target and environment. The LRF3000A1 figure is tied to a 70 % reflectivity building and visibility of 4 km or more. The LRF1500H page gives two ranges on one line: 1,500 m at 90 % reflectivity but only 300 m at 10 %. Dark rock, wet asphalt and vegetation sit nearer the second number than the first.
Rate separates the two camps. The kilometre-class bare modules (LR series, LRF3000A1, SPD) read a few times per second. The Benewake TFA1500-L adapts between 60 and 800 Hz, and the LRF1500H switches between 50 Hz and 1 kHz depending on signal strength. If you are closing a control loop, that matters more than another 500 m of reach. If you are mapping a ridge line or watching a tower, 5 Hz is plenty.
Supply and interface differ in a way that bites on day one. The bare modules run from 3.3-5 V and speak UART. The H series wants 9-36 V and offers UART or I2C. Check the logic level of TXD/RXD against your microcontroller before you connect anything. The LRF3000A1 page says 3.3 V TTL; for the others, confirm in the manual.
Run the accuracy rules yourself
The datasheet rules are easy to misread, so here is a script that evaluates them. Save it as accuracy_at_distance.py and run python accuracy_at_distance.py (standard library only; I ran it before posting).
# accuracy_at_distance.py - published accuracy rules, evaluated at the distance you care about
RULES = { # model: list of (upper_distance_m, fixed_m, per_metre_fraction), checked 2026-11-07 on erdilrf.com
"LR1000E2": [(400, 1.0, 0.0), (1000, 1.0, 0.001)],
"LR1500E2": [(500, 1.0, 0.0), (1500, 0.5, 0.001)],
"LR2000E2": [(400, 1.0, 0.0), (2000, 0.0, 0.004)],
"LRF3000A1": [(100, 0.7, 0.0), (3000, 0.7, 0.003)],
"SPD1200S2": [(400, 0.3, 0.0), (1200, 0.5, 0.001)],
}
def accuracy_m(model, d):
for upper, fixed, frac in RULES[model]:
if d <= upper:
return fixed + frac * d
raise ValueError(f"{model}: {d} m is beyond the published range")
if __name__ == "__main__":
for d in (100, 400, 800, 1000, 1200):
row = []
for m in RULES:
try:
row.append(f"{m} +/-{accuracy_m(m, d):.1f} m")
except ValueError:
row.append(f"{m} n/a")
print(f"{d:>5} m " + " | ".join(row))
Sample output from that run:
800 m LR1000E2 +/-1.8 m | LR1500E2 +/-1.3 m | LR2000E2 +/-3.2 m | LRF3000A1 +/-3.1 m | SPD1200S2 +/-1.3 m
1200 m LR1000E2 n/a | LR1500E2 +/-1.7 m | LR2000E2 +/-4.8 m | LRF3000A1 +/-4.3 m | SPD1200S2 +/-1.7 m
The LR1500E2 rule comes from a page that says its two sources differ on where the second interval ends, so confirm the revision you are shipped.
Which one for which job
- Drone terrain-ahead, structure distance, cable-span measurement: a 1.2-2 km bare module. Pair it with a separate fast short-range sensor for altitude. A 2-10 Hz sensor is not an altitude-hold sensor.
- Fixed monitoring posts, tower or slope distance checks: the cheapest model that covers your distance with margin. Buy the next range up; real surfaces are not 90 % white boards.
- Robot or AGV obstacle sensing under 300 m: the H series (LRF300H, LRF600H) or a short-range VB part, because the high rate is what you need there. LRF50VB is 1.3 g and listed at USD 70.
- More than 3 km: this is a different product class. The longer-range ERDI parts use 1535 nm lasers and RS-422 at 12 V; they are listed on the 1535 nm rangefinder page and are priced in the hundreds to thousands of dollars.
Reading one over UART
If you pick an LR-series module, the protocol is an 8-byte request and an 8-byte reply: 55 AA <function> D1 D2 D3 D4 <checksum>. Single-shot ranging is 55 AA 88 FF FF FF FF 84. The reply carries the distance as an actual-value-times-ten integer. A complete Python reader with checksum handling is in the ERDI Raspberry Pi example repository, and the machine-readable model table is in the laser rangefinder module database.
Caveats
- ERDI TECH LTD is the author's company. I included a competitor's published numbers because a shortlist that hides them is not worth reading.
- Missing cells mean the number was not on the public page I read. Pull the PDF before you design a board.
- Prices and ranges change; the product pages are the source of truth.
The full model list with datasheet links is at https://erdilrf.com/models/, and the 1-2 km pages are at https://erdilrf.com/lrf/1km-laser-rangefinder-module/ and https://erdilrf.com/lrf/2km-laser-rangefinder-module/.
Data checked 2026-11-07. Tommy Yu, ERDI TECH LTD, erdilrf.com
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