DD-303N / DD-403N Wide-slot Photoelectric Sensor

Name: DD-303N / DD-403N Wide-slot Photoelectric Sensor
Brand: DAIDISIKE
SKU: dd-303n-dd-403n-wide-slot-photoelectric-sensor
Availability: InStock

13 mm through-beam slot sensor giving real tolerance for thick or fluttering parts, still detecting down to 2.2×0.5 mm.

DD-303N / DD-403N Wide-slot Photoelectric Sensor - product photo

🔍 Click to enlarge · 1/7

Technical Specifications

Detection method	Through-beam (slot/fork), 13 mm gap
Light source	GaAs infrared LED, 940 nm
Output type	NPN output; DD-403N-1 variant confirmed Light-ON (normally open)
Minimum detectable object	2.2×0.5 mm
Hysteresis (differential travel)	0.05 mm max
Response frequency	100 Hz min
Supply voltage	DC 5-24V ±10%
Current consumption	15 mA max
Protection rating	IP50

Overview

The DD-303N and DD-403N are through-beam (slot/fork) photoelectric sensors with a 13 mm detection gap, using a 940 nm GaAs infrared emitter and NPN output. They detect via light interruption between the emitter and receiver mounted in the same slot body, and are built for machine builders and OEMs handling objects that do not travel through the gap on a perfectly fixed, narrow path.

The 13 mm slot is wider than the 5 mm gap used across the rest of the company's slot-sensor line, giving real tolerance for thicker parts or material that flutters or wanders slightly within the gap, without sacrificing sensitivity to fine objects down to 2.2×0.5 mm. Hysteresis is 0.05 mm maximum for a crisp switching point, response frequency is 100 Hz minimum, and the sensor runs on a DC 5-24V (±10%) supply drawing 15 mA maximum.

Features & Benefits

13 mm Wide Slot for Real Mechanical Tolerance

The detection gap is 13 mm, wider than the 5 mm slot used across the rest of the company's slot-sensor line. Thicker workpieces or material that flutters or wanders slightly within the gap can be detected reliably without mechanical fine-tuning.

Fine-Object Sensitivity Despite the Wider Gap

Even with the wider slot, the sensor still resolves objects as small as 2.2×0.5 mm, such as a thin sheet edge or a small protruding tab.

0.05 mm Max Hysteresis for a Crisp Switching Point

Differential travel is 0.05 mm maximum, so the on/off switching point stays tight as the target moves in and out of the beam, useful for edge position or float-flag applications that need a clean, non-chattering trigger.

940 nm GaAs Infrared Emitter

The gallium-arsenide infrared LED operates at 940 nm, outside the visible spectrum, reducing direct interference from ordinary shop lighting.

Wide 5-24 VDC Supply, Low 15 mA Draw

The sensor accepts a 5-24 VDC (±10%) supply and consumes 15 mA maximum, so it runs directly from low-voltage board-level rails or standard 24V industrial circuits, keeping power budget low even with multiple units installed on one machine.

NPN Output with a Confirmed Light-ON Variant

The base models use NPN output; the DD-403N-1 variant is confirmed to switch ON when the beam is received (Light-ON, normally open), letting customers match output logic to their control-signal requirement.

Applications

Sheet or Web Edge Position Detection — The 13 mm slot allows an edge to flutter slightly up and down within the gap and still be detected reliably, while 0.05 mm hysteresis keeps the trigger point crisp.

Thicker Workpiece or Packaged-Part Presence Detection — The 13 mm gap accommodates thicker parts than a standard 5 mm slot sensor can pass, without mechanical rework.

Float-Flag Style Level Indication — Where a flag moves within a wide slot, the 13 mm gap gives room for the flag's travel while 0.05 mm hysteresis keeps the switching point stable.

Coarse Web or Roll Misalignment Detection — The wide slot's tolerance suits detecting whether material has wandered outside its normal path, as a presence/position check rather than precision guiding.

General Slot-Type Sensing Where a 5 mm Gap Is Too Tight — For any presence or position sensing application where a standard 5 mm slot sensor's gap is too tight, the 13 mm gap provides more mechanical tolerance.

Models & Ordering Information

Base Series (NPN Output)

DD-303NDD-403N

Output-Logic Variants

DD-303N-1DD-403N-1

DD-403N-1 is confirmed Light-ON (normally open); DD-303N-1 switching logic is not yet confirmed for publication.

How to Select

All models are NPN output; choose DD-403N-1 for confirmed Light-ON (normally open) switching logic.
The 13 mm slot is the widest in the company's slot-sensor line, so prioritize this series when detected parts are thick, flutter, or have loose path tolerance.
Sensitivity is not sacrificed by the wider slot: minimum detectable object remains 2.2×0.5 mm.
Supply voltage DC 5-24V (±10%) accepts either 5V board-level power or a 24V industrial circuit; budget 15 mA max per unit.
IP50 is dust-protected only, with no water protection, so it is intended for indoor, dry-environment use only.

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

When NOT to specify the DD-303N — and what to use instead

The part or wire to be detected is smaller than roughly 2.2x0.5 mm

Why not: The DD-303N/DD-403N's minimum detectable object is 2.2x0.5 mm; the 13 mm gap is optimized for width tolerance, not for resolving objects finer than that figure.

Use instead: a micro-slot model such as DD-L25/L45, which is built around a smaller minimum detectable object

The target is thicker or wider than the 13 mm gap, or cannot be routed through a fixed U-shaped slot at all

Why not: This is a through-beam slot sensor with a fixed 13 mm detection gap; anything that will not physically pass between the emitter and receiver in that gap cannot be detected.

Use instead: a standard through-beam photoelectric sensor with separate emitter/receiver units for larger or free-standing objects that won't fit any slot

The application needs a PNP output or an on-site NO/NC wiring selection

Why not: The specs list NPN output as standard, with only the DD-403N-1 variant confirmed for Light-ON (normally open) logic; no PNP version or field-selectable logic is documented for this series.

Use instead: the DD-670 series, which offers N/P/NA/R output-and-logic variants across its housing styles

The equipment operates outdoors, in a washdown area, or anywhere water spray is expected

Why not: Protection rating is IP50, which the selection guide notes is dust-protected only with no water protection, intended for indoor, dry-environment use.

Use instead: an IP65-rated slot sensor such as DD-L25/L45 for splash-exposed installations

The line needs to count fast-moving or closely-spaced small parts

Why not: Response frequency is only specified as 100 Hz minimum, which the FAQ describes as suited to position/presence detection at low-to-moderate speeds rather than high-speed counting.

Use instead: a slot sensor with a documented sub-millisecond response time, such as FS-KNS (0.3 ms max.), for high-speed counting duty

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.

Slot depth (how far the object can be inserted into the fork) is not stated in the source material
MTBF / rated mechanical or electrical lifetime is not stated
Operating and storage temperature range is not stated
Cable length and connector/terminal type are not stated
PNP output availability for this series is not confirmed either way
DD-303N-1 switching logic (Light-ON vs Dark-ON) is explicitly noted in the source as not yet confirmed for publication
No certification documents are published on the product page; available on request only, specific standards/marks not stated
External housing dimensions and mounting-hole pattern are not stated

Frequently Asked Questions

What is the detection gap size of the DD-303N / DD-403N?

The detection gap (slot width) is 13 mm, a through-beam (slot/fork) type sensor.

What is the minimum object size these sensors can detect?

The minimum detectable object is 2.2×0.5 mm.

What is the hysteresis (differential travel) of the sensor?

The hysteresis is 0.05 mm maximum.

What light source and wavelength do these sensors use?

A GaAs (gallium arsenide) infrared emitter at 940 nm.

What is the output type, NPN or PNP?

NPN output. No PNP variant is documented for this specific 13 mm wide-slot series in current source material.

What is the supply voltage and current consumption?

DC 5-24V (±10%) supply, with 15 mA maximum current consumption.

What is the response frequency, and is it suitable for high-speed counting?

The response frequency is 100 Hz minimum, which suits position/presence detection at low-to-moderate speeds; it is not positioned as a high-speed counting sensor.

Is this sensor waterproof or suitable for wet/washdown environments?

No. The IP rating is IP50 (dust-protected, no water protection), so it is intended for indoor, dry-environment use only.

Is there a Light-ON (normally open) output variant?

Yes, the DD-403N-1 variant is confirmed to switch ON when light is received (Light-ON, normally open).

How is this sensor different from the company's standard 5 mm slot sensors?

This series uses a 13 mm slot, roughly 2.6 times wider than the 5 mm slot used on the company's other slot-type sensors, giving more mechanical tolerance for thicker or loosely-guided parts.

Can you provide certification documents for the DD-303N / DD-403N?

Certification documents are available on request.

Works Well Together

On the same machine or line, DD-303N is typically ordered together with: Photoelectric Sensors · Fiber Optic Sensors · Proximity Sensors

Related Products in Slot Sensors

Browse all Slot Sensors →