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.
🔍 Click to enlarge · 1/17Technical Specifications
| Type | Miniature laser through-beam (opposed) photoelectric switch |
|---|---|
| Light Source | 650nm red laser |
| Detection Method | Through-beam (transmitter + receiver pair) |
| Detection Distance | M3/M4/M5/M6: 20m; M8: 30m |
| Output | NPN / PNP, NO (suffix 1) / NC (suffix 2) |
| Operating Voltage | 10-30VDC |
| Thread Size | M3 / M4 / M5 / M6 / M8 |
| Protection Rating | IP65 |
Overview
This is a through-beam (opposed) laser photoelectric switch: a separate transmitter and receiver unit, each in an ultra-small M3, M4, M5, M6 or M8 threaded metal housing, mounted facing each other so the object to be detected passes between them. The transmitter emits a 650nm red laser beam; the receiver detects when that beam is interrupted. It is built for machine builders and automation integrators who need to detect small, thin, or closely-spaced parts in confined mounting spaces where a standard-size M12/M18 photoelectric sensor will not physically fit.
Because the housings are miniaturized down to M3 thread and the laser spot is tight (as small as approximately 1.5mm standard on the M3/M4/M5 through-beam versions), the sensor pair can still reach detection distances of up to 20m on the M3/M4/M5/M6 units and up to 30m on the M8 unit. Each thread size is offered in NPN or PNP transistor output, further available in normally-open (NO) or normally-closed (NC) logic, on a 10-30VDC supply, for direct wiring into a PLC input card.
Features & Benefits
Ultra-small thread sizes fit where standard sensors can't
M3, M4, M5, M6, M8 metal threaded housings (M3x20mm up to M8x45mm body) let the sensor pair mount into tight brackets, narrow slots, or closely spaced machine frames.
Fine 1.5mm laser spot for small/narrow target detection
The M3/M4/M5 through-beam spot size is standard ~1.5mm, small enough to reliably catch narrow parts, thin gaps, or closely-pitched objects that a wider infrared beam would miss.
Long detection range for such a small housing
Up to 20m for M3/M4/M5/M6 and up to 30m for M8, letting one transmitter-receiver pair span long conveyor lines or wide machine openings despite the miniature body size.
Flexible output configuration for direct PLC wiring
NPN or PNP transistor output, each available in normally-open (NO) or normally-closed (NC) logic (order code suffix N1/P1 = NO, N2/P2 = NC), DC 3-wire connection.
10-30VDC wide voltage range with built-in protection
Operates across a broad 10-30VDC supply band and includes short-circuit protection, reducing risk of sensor damage from wiring mistakes or supply fluctuation on the factory floor.
IP65 protection for washdown and dusty environments
Sealed to IP65, suitable for factory environments with dust, splashing water, or coolant/oil mist typical of packaging, food processing, and machining lines.
Fast 5ms response for high-speed lines
A 5ms response time and 100Hz switching frequency, per the factory selection table covering the M3/M4/M5 through-beam models (all thread sizes M3-M8), support detection of fast-moving small parts on high-speed conveyors or indexing equipment.
Visible status LEDs for fast commissioning and troubleshooting
The M3/M4/M5 transmitter has a green LED and the receiver a yellow LED, giving installers an at-a-glance way to confirm the beam is emitting and being received during alignment.
Applications
Models & Ordering Information
M3 Thread (20m range)
M4 Thread (20m range)
M5 Thread (20m range)
M6 Thread (20m range)
M8 Thread (30m range)
How to Select
- Step 1 — Detection distance: M3, M4, M5, M6 units cover up to 20m; the M8 unit covers up to 30m, so choose based on how far apart the transmitter and receiver need to be mounted.
- Step 2 — Thread size / installation space: pick M3x0.5mm (body 20mm), M4x0.5mm (body 20mm), M5x0.5mm (body 24mm), M6x0.5mm (body 26mm), or M8x1mm to match your mounting hole and available clearance.
- Step 3 — Output transistor type: match NPN (sinking) or PNP (sourcing) to your PLC/controller input card type; both are offered across all thread sizes.
- Step 4 — Output logic: order-code suffix "1" (N1/P1) means normally open (NO); suffix "2" (N2/P2) means normally closed (NC) — choose based on whether your control logic needs the output to activate or de-activate when the beam is blocked.
- Step 5 — Power supply: confirm your control cabinet supply falls within the 10-30VDC operating range shared by all models.
- Order code pattern: DS + thread size code (03/04/05/06/08) + range in meters (20 or 30) + M (through-beam) + N/P (NPN/PNP) + 1/2 (NO/NC), e.g. DS0320MN1 = M3, 20m, NPN, NO.
📘 Need the full method? NPN vs PNP Sensor Outputs Explained
When NOT to specify the DS — and what to use instead
A transmitter-to-receiver span longer than this family supports
Why not: Rated detection distance tops out at 20m for the M3/M4/M5/M6 threads and 30m for M8; longer spans exceed this miniature family's range.
Use instead: the M12/M18 laser through-beam pair rated to 50m
Only one side of the target is accessible for a sensor
Why not: This is a through-beam pair: the transmitter and receiver must be mounted facing each other with the object passing between them.
Use instead: a laser diffuse model where only one mounting point is available
Detecting fully transparent or very dark, highly light-absorbing targets
Why not: The product's own FAQ states detection distance and reliability depend on the target's color, reflectivity, and surface finish, and recommends confirming transparent-object feasibility with technical support before ordering.
Use instead: check with the factory on transparent/dark-target feasibility, or consider a diffuse sensor suited to the surface type
Machine guarding or personnel-safety interlocking
Why not: Only IP65, 10-30VDC, and a general certification-on-request note are documented; no safety-rated certification is claimed for this switch.
Use instead: a dedicated safety light curtain for any guarding function
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 (only 650nm wavelength is documented)
- Laser spot size for the M6/M8 units (only the M3/M4/M5 ~1.5mm spot is documented)
- MTBF
- Exact operating/storage temperature range
- Cable length and connector style
- Certification (CE/UL/RoHS etc.)
Frequently Asked Questions
What is the difference between the M3, M4, M5, M6 and M8 versions of this sensor?
Is this a through-beam (opposed) or diffuse-reflective sensor?
What output types are available — NPN or PNP, NO or NC?
What is the smallest object this sensor can detect?
What is the IP rating and operating voltage?
Can this sensor detect transparent or dark-colored objects?
How do I align the transmitter and receiver?
What is the response time and switching frequency?
Does this sensor come with certification documents?
Works Well Together
On the same machine or line, DS 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 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.
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 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.