DS Laser Through-Beam Sensor M12/M18 (50m)

Name: DS Laser Through-Beam Sensor M12/M18 (50m)
Brand: DAIDISIKE
SKU: ds-laser-through-beam-sensor-m12-m18
Availability: InStock

M12/M18 laser through-beam sensor pair, 50m range, NPN/PNP output, NO or NO+NC, IP65 rated.

DS Laser Through-Beam Sensor M12/M18 (50m) - dimensional drawing

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Technical Specifications

Type	Laser through-beam (opposed-mode) photoelectric sensor, long range
Light Source	650nm red laser
Detection Mode	Through-beam (matched transmitter + receiver pair)
Detection Distance	M12: 50m; M18: 50m
Output Type	NPN / PNP; 3-wire NO (suffix "1") or 4-wire NO+NC (suffix "11")
Operating Voltage	10-30VDC
Thread Size	M12 / M18
Protection Rating	IP65

Overview

The DS Series M12/M18 laser through-beam sensor is a through-beam (opposed-mode) photoelectric sensor pair: a separate laser transmitter and receiver are installed facing each other, and an object is detected when it interrupts the laser beam between them. It is built into a threaded M12 or M18 metal housing for direct mounting on machine frames, gates, or racking with standard nuts.

Both the M12 and M18 versions are rated for a 50-meter detection distance and use a 650nm red laser light source for easy visual alignment. The sensor is available in NPN or PNP output, with a 3-wire single normally-open (NO) signal or a 4-wire output providing both NO and NC signals, operates on 10-30VDC, and carries an IP65 protection rating.

Features & Benefits

50-Meter Detection Range in M12 and M18

Both the M12 and M18 versions of this through-beam pair are rated for a 50-meter detection distance. This covers long spans such as wide aisles, large doors, or long conveyor lines without adding intermediate sensors.

650nm Red Laser for Visible Alignment

The transmitter emits a visible 650nm red laser, making it easier for installers to visually confirm beam alignment between transmitter and receiver during setup, compared to invisible infrared beams.

NPN and PNP Output Options

Both M12 and M18 versions are offered in NPN and PNP output variants, letting engineers match the sensor to sinking or sourcing input PLCs/controllers without external interposing relays.

Selectable 3-Wire NO or 4-Wire NO+NC Output

Each output type is available as a 3-wire single normally-open (NO) output (suffix "1") or a 4-wire output providing both NO and NC signals simultaneously (suffix "11"), giving designers a choice between simple detection and dual-signal logic.

10-30VDC Wide Voltage Range

The sensor operates across a 10-30VDC input range, compatible with common 12VDC and 24VDC industrial control power supplies without a separate voltage regulator.

IP65-Rated Housing

The IP65 protection rating means the housing is dust-tight and protected against water jets, suitable for use in workshops with dust, splashing, or periodic hose-down cleaning.

Standard M12/M18 Threaded Metal Body

The sensor pair uses an industry-standard M12 or M18 threaded cylindrical housing, allowing mounting through a drilled panel or bracket with standard nuts, matching common photoelectric sensor mounting practice.

Applications

Long-Aisle or Gate Presence Detection in Warehouses — The 50m through-beam range covers wide openings that a diffuse reflective sensor, which reflects off the object itself, typically cannot reach.

Large Object or Pallet Counting on Conveyor Lines — Through-beam mode reliably triggers on interruption regardless of the object's surface color or reflectivity, unlike diffuse reflective detection which depends on target reflectivity.

Access Point Monitoring (Non-Safety-Rated) — The through-beam pair can signal when a beam path across an opening is broken, useful for basic presence/interruption signaling in general automation, not as a certified safety device.

Long-Span Machine Guarding Perimeter Interruption Detection — The 50m range and NO+NC output option support logic circuits that need both a positive and negative confirmation signal across a monitored line.

Outdoor or Semi-Outdoor Equipment Position Detection — The IP65 housing and visible red laser support installation in dusty or splash-exposed outdoor equipment where beam alignment needs to be visually verifiable.

Elevator, Hoist, or Gate Open/Closed Status Detection — Through-beam interruption logic gives a clear binary signal for whether a path or opening is clear or obstructed.

AS/RS Aisle-End Detection — The long 50m range suits detecting carriage or shuttle presence at the far end of long racking aisles.

Bulk Material or Stacked-Object Edge Detection — The threaded M12/M18 body allows mounting transmitter and receiver on opposite sides of wide production lines.

Models & Ordering Information

M12 Through-Beam (50m)

DS1250MN1DS1250MN11DS1250MP1DS1250MP11

MN1 = NPN 3-wire NO; MN11 = NPN 4-wire NO+NC; MP1 = PNP 3-wire NO; MP11 = PNP 4-wire NO+NC

M18 Through-Beam (50m)

DS1850MN1DS1850MN11DS1850MP1DS1850MP11

MN1 = NPN 3-wire NO; MN11 = NPN 4-wire NO+NC; MP1 = PNP 3-wire NO; MP11 = PNP 4-wire NO+NC

How to Select

M12 and M18 share the same 50m detection range in this series; choose based on mounting hole size and mechanical strength — M12 suits smaller brackets/panels, M18 offers a thicker housing for higher mechanical strength.
Choose NPN (model contains "N", e.g. DS1250MN1) for sinking-input PLCs, or PNP (model contains "P", e.g. DS1250MP1) for sourcing-input PLCs; match this to your control system's input type.
Choose the "1" suffix (3-wire, single NO output) for simple presence/absence signaling, or the "11" suffix (4-wire, NO+NC output) when dual-signal interlock or wire-break/fault detection is needed.
Confirm the supply voltage falls within 10-30VDC; this range covers common 12VDC and 24VDC industrial supplies without extra regulation.
Each model number represents a matched transmitter-and-receiver pair; order complete pairs according to the number of detection points, not a single half.

📘 Need the full method? NPN vs PNP Sensor Outputs Explained

When NOT to specify the DS — and what to use instead

Only one side of the target is accessible for mounting

Why not: This is a through-beam (opposed-mode) sensor: a matched transmitter and receiver must be installed facing each other across the gap, so a single mounting point isn't enough.

Use instead: a laser diffuse model where only one mounting point is available

The target is fully transparent, or the beam path can't run in a straight line

Why not: Through-beam detection depends on the object physically interrupting a straight 650nm laser path between transmitter and receiver; the documented specs don't address transparent targets or bent beam paths.

Use instead: confirm transparent-target feasibility with the factory, or evaluate a diffuse-reflective sensor tuned to the surface

A compact, short-range single-point detection task in a tight mounting space

Why not: This series is built around a fixed 50m range in a full-size M12/M18 threaded barrel meant for long spans, not for close-range detection in a small footprint.

Use instead: a diffuse laser sensor in a smaller body for short-range single-point detection

Machine guarding or personnel access-point safety interlocking

Why not: Documented ratings cover only IP65 and 10-30VDC; the FAQ notes certification documents are available on request, but no safety-function certification is claimed in the specs themselves.

Use instead: a dedicated safety light curtain, never this through-beam switch, 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)
Minimum detectable object size/width
Response time / switching frequency
Hysteresis (repeat accuracy)
MTBF
Exact operating temperature range
Cable/connector specification
Certification (CE/UL/RoHS etc.)

Frequently Asked Questions

What is the detection range of the DS M12 and M18 laser through-beam sensors?

Both the M12 and M18 versions in this series are rated for up to 50 meters detection distance between the transmitter and receiver.

What is the difference between the M12 and M18 versions?

Both share the same 50m detection range, 650nm red laser, IP65 rating, and 10-30VDC supply; the difference is the thread/housing size (M12 vs M18), which affects mounting hole diameter and mechanical robustness.

What output types are available — NPN or PNP?

Both are available. Model codes containing "N" (e.g., DS1250MN1) are NPN output; model codes containing "P" (e.g., DS1250MP1) are PNP output.

What is the difference between the "1" and "11" suffix models?

The "1" suffix (e.g., MN1, MP1) is a 3-wire output with a single normally-open (NO) signal. The "11" suffix (e.g., MN11, MP11) is a 4-wire output providing both a normally-open (NO) and a normally-closed (NC) signal simultaneously.

How does a through-beam (opposed-mode) sensor differ from a diffuse reflective sensor?

A through-beam sensor uses two separate units — a transmitter and a receiver — installed facing each other; detection occurs when an object breaks the beam path between them. A diffuse reflective sensor uses a single unit that emits light and detects light reflected back off the target itself, which makes its range and reliability more dependent on the target's surface and color.

What light source does this sensor use?

A 650nm red laser, which is visible to the human eye and helps installers visually confirm alignment between the transmitter and receiver during setup.

What is the supply voltage range?

10-30VDC.

What is the ingress protection (IP) rating?

IP65, indicating a dust-tight enclosure protected against water jets.

Do I need to order the transmitter and receiver separately?

No — each listed model number represents a matched transmitter-and-receiver pair for through-beam operation; they are used together as one detection point.

Is this sensor rated as a certified safety device (e.g., for machine guarding safety functions)?

No -- this is a general-purpose laser through-beam sensor with no safety-function rating (no Type / SIL / PL). For machine guarding or personnel protection, use a safety light curtain (DQC / DQA) or the ST27 safety laser scanner. General certification documents are available on request.