DDSK Laser Diffuse Reflective Sensor M12 / DK Laser Diffuse Reflective Sensor M18
M12/M18 threaded laser diffuse reflective sensor with a visible 650nm red laser for fast alignment.
🔍 Click to enlarge · 1/5Technical Specifications
| Type | Laser diffuse reflective photoelectric switch |
|---|---|
| Light source | 650nm red laser |
| Detection method | Diffuse reflective |
| Detection distance | M12: 20-200mm / 20-300mm; M18: 50-300mm / 70-500mm |
| Output type | NPN / PNP; suffix 1 = normally-open NO (3-wire); suffix 2 = 4-wire (NO+NC) |
| Operating voltage | 10-30VDC |
| Thread size | M12 (DDSK) / M18 (DK) |
| Protection rating | IP65 |
Overview
The DDSK M12 and DK M18 are diffuse reflective (proximity-style) laser photoelectric switches: the sensor emits a 650nm visible red laser beam and detects the light reflected back from the target itself, without requiring a separate reflector or receiver unit. Housed in a threaded M12 (DDSK) or M18 (DK) barrel, they suit machine builders, panel integrators, and OEMs who need a single-point object-presence sensor that mounts quickly on standard threaded brackets and is easy to align visually thanks to the visible laser spot.
Each sensor is available in NPN or PNP transistor output, with either a 3-wire normally-open (NO) output or a 4-wire NO+NC output, on a 10-30VDC supply. The DDSK M12 series covers a 20-200mm or 20-300mm detection distance for compact, close-range mounting, while the DK M18 series extends to 50-300mm or 70-500mm for longer working distances.
Features & Benefits
Visible Laser Spot for Fast Alignment
The 650nm red laser is visible to the human eye, letting installers see exactly where the beam hits the target during mounting and adjustment, without needing an oscilloscope or indicator-only trial and error.
No Reflector Required
As a diffuse reflective sensor, it detects light reflected directly from the target surface, eliminating the extra reflector/mirror and the second mounting point that through-beam or retroreflective sensors require.
Two Threaded Body Sizes Covering Short to Mid-Range Detection
DDSK (M12) covers 20-200mm or 20-300mm detection distance for compact, close-range applications; DK (M18) extends to 50-300mm or 70-500mm for longer working distances, letting integrators match sensor size to the mounting envelope and range needed.
NPN and PNP Output Both Available
Every detection-distance/size combination is offered in both NPN and PNP transistor output, so the sensor can be wired into either sinking or sourcing PLC input cards without needing a separate interposing relay.
Simple 3-Wire or 4-Wire (NO+NC) Output Selection
Suffix "1" models give a straightforward 3-wire normally-open (NO) output for basic on/off detection; suffix "2" models add a 4-wire NO+NC output, giving both a normal and inverted signal from one sensor for redundant logic or fail-safe wiring without adding a second sensor.
Wide Supply Voltage Range
Operating on 10-30VDC, the sensor fits directly into common 12VDC and 24VDC industrial control power rails without a dedicated voltage regulator.
IP65-Rated Housing
The IP65 protection rating means the housing is dust-tight and protected against water jets from any direction, suiting use on dusty workshop floors or areas exposed to washdown/splash without a separate enclosure.
Threaded Barrel Design for Standard Mounting
The M12 (DDSK) and M18 (DK) cylindrical threaded body fits common photoelectric sensor mounting brackets and nuts already used across the machine-building industry, simplifying bracket sourcing and replacement.
Applications
Models & Ordering Information
DDSK Diffuse Reflective M12 — 20-200mm Detection Distance
DDSK Diffuse Reflective M12 — 20-300mm Detection Distance
DK Diffuse Reflective M18 — 50-300mm Detection Distance
DK Diffuse Reflective M18 — 70-500mm Detection Distance
How to Select
- M12 thread (DDSK series) suits a more compact mounting space with a detection distance up to 300mm.
- M18 thread (DK series) suits applications needing a longer detection distance (up to 500mm) or an M18 mounting hole.
- DDSK-122xx (M12, 20-200mm) is the shortest-range option in this series.
- DDSK-123xx (M12, 20-300mm) is the longer-range option within the M12 body size.
- DK-183xx (M18, 50-300mm) is the shorter-range option within the M18 body size.
- DK-185xx (M18, 70-500mm) is the longest-range option in this series.
- Actual effective detection distance depends on the target's color, reflectivity, and surface material.
- Choose NPN if your PLC/controller input card is sinking-type; choose PNP if it is sourcing-type. In the model number, "N" denotes NPN and "P" denotes PNP (e.g., DDSK-12200N1 is NPN, DDSK-12200P1 is PNP).
- Choose suffix "1" (N1/P1) for a 3-wire normally-open (NO) output when basic on/off detection is enough.
- Choose suffix "2" (N2/P2) for a 4-wire NO+NC output when you need an inverted signal or redundant logic.
- Confirm your supply falls within 10-30VDC, which covers common 12VDC and 24VDC sources.
- If the mounting point is exposed to dust or washdown water jets, the IP65 rating already covers basic protection without an additional enclosure.
📘 Need the full method? NPN vs PNP Sensor Outputs Explained
When NOT to specify the DDSK — and what to use instead
Detecting dark, matte, or low-reflectivity targets near the far end of the rated range
Why not: As a diffuse reflective sensor, effective detection distance depends on the target's color, reflectivity, and surface material (per the product's own selection guide), so a 20-300mm (M12) or 70-500mm (M18) rating on a bright target can fall well short on a dark or matte one.
Use instead: a laser through-beam pair for long range and reliability regardless of target surface
A detection point beyond 500mm, or spanning a wide opening or aisle
Why not: The longest rated range in this series is the DK-18500 (M18) at 70-500mm; there is no longer-range diffuse variant in this family.
Use instead: a laser through-beam pair rated for tens of meters
Machine guarding or personnel-safety interlocking
Why not: The documented specs cover only IP65 dust/water protection and a 10-30VDC electrical rating; no safety function or safety certification is included.
Use instead: a dedicated safety light curtain, never a diffuse proximity sensor, for guarding a hazard zone
A regulated design that must cite a laser safety class or a validated operating-temperature range
Why not: The spec sheet documents only the 650nm wavelength; laser class and operating temperature are not stated anywhere in the current data.
Use instead: request the missing ratings from the factory before citing this sensor in a compliance file
Specifications we do not publish yet
We only publish a figure once we are confident it is true. The items below are still being validated through further testing and real-world customer feedback, so for now we would rather leave them open than guess. If one of them matters to your design, ask us for the latest validated status.
- Laser safety class (e.g., Class 1/2) — only the 650nm wavelength is documented
- Minimum detectable object size/diameter
- Hysteresis (repeat accuracy)
- Response time / switching frequency
- MTBF
- Exact operating/storage temperature range
- Cable length, cable type, or connector style
- Certification (CE/UL/RoHS etc.)
Frequently Asked Questions
What is the difference between the DDSK M12 and DK M18 laser diffuse reflective sensors?
Do I need a separate reflector for these sensors?
What is the difference between suffix "1" and suffix "2" models (e.g., N1 vs N2)?
How do I choose between NPN and PNP output?
What is the operating voltage range?
What is the light source, and is it visible during alignment?
What ingress protection rating do these sensors carry?
What is the maximum detection distance available in this series?
Can DAIDISIKE provide certification documents for the DDSK/DK series?
Works Well Together
On the same machine or line, DDSK is typically ordered together with: Photoelectric Sensors · Fiber Optic Sensors · Slot Sensors
BGS-CX441 / BGS-CX442 Background Suppression Photoelectric Sensor
Wire-adjustable BGS sensor with 2 mm or 15 mm spot, 10-300 mm range, published black/white differential distance.
Fiber Amplifier (Digital Fiber Optic Sensor Amplifier)
Digital fiber optic amplifiers with NPN/PNP output, from potentiometer economy models to 25µs dual-display smart units.
DD-303N / DD-403N Wide-slot Photoelectric Sensor
13 mm through-beam slot sensor giving real tolerance for thick or fluttering parts, still detecting down to 2.2×0.5 mm.
Related Products in Laser Switch Sensors
DDSK Ultra-Miniature Laser Diffuse Reflective Sensor (M3/M4/M5/M6/M8)
Ultra-miniature M3-M8 threaded laser diffuse sensor, 650nm laser, no reflector, 10-30VDC, IP65.
DS Laser Through-Beam Sensor M12/M18 (50m)
M12/M18 laser through-beam sensor pair, 50m range, NPN/PNP output, NO or NO+NC, IP65 rated.
DS Miniature Laser Through-Beam Sensor (M3/M4/M5/M6/M8)
Ultra-small M3-M8 laser through-beam sensor pair detects tiny parts up to 20-30m, NPN/PNP, NO/NC output.
DS Right-Angle (90°) Laser Through-Beam Switch M4 / M6
90° right-angle M4/M6 laser through-beam switch with a 1.5-2mm spot and 20m detection range for tight spaces.