A fork sensor puts the transmitter in one arm of a U-shaped housing and the receiver in the other, permanently aligned at the factory. You get through-beam accuracy with none of the alignment work — bolt it on and it simply runs.
Through-beam accuracy without the alignment
The single biggest cause of photoelectric downtime is drift: vibration or an accidental knock nudges an emitter, the beam wanders off the receiver, and the line stops. A fork sensor removes that failure mode entirely because both optical elements are fixed in one rigid casting. The gap is set at manufacture and cannot change.
That mechanical stability is exactly what high-speed label and small-part detection needs, where the object may be only a millimetre or two across.
Key features
- No alignment required — emitter and receiver are pre-aligned in one housing.
- High precision on tiny objects such as labels, perforations and small components.
- Compact U-shaped body fits confined spaces on packaging and printing machinery.
- Fast replacement — plug-and-play mounting minimises downtime.
- Corrosion resistant for humid and dusty environments.
- 4 m cable as standard, easing panel routing.
Technical specifications
| Parameter | Value |
|---|---|
| Sensor type | Fork — U-shaped through-beam |
| Fork gap | 12 mm |
| Output | PNP, normally open (positive logic) |
| Operating voltage | 30 V DC |
| Maximum load current | 300 mA |
| Frequency | 50 Hz |
| Housing material | Mild steel |
| Colour | Black |
| Corrosion resistance | Yes |
| Cable length | 4 m |
| Product code | 21420 |
Typical applications
- Label detection — verifying presence and absence on packaging lines.
- Perforated disc scanning — counting holes or slots on rotating discs.
- Small part detection in assembly automation.
- Bottle cap inspection on filling machines.
- Textile and printing machines — monitoring thread breaks and misprints.
How to order
Tell us the sensing gap, the target material, your supply voltage and the output type your controller needs. If you are replacing an existing sensor, a photograph of the body markings is usually enough for us to identify an equivalent. We will confirm the specification and quote — normally the same day.
Related products
Frequently asked questions
What is the difference between a fork sensor and a slot sensor?
The housing shape is similar but the sensing technology is not. Our slot sensor is inductive and detects metal only. The fork sensor is photoelectric and detects anything opaque — labels, paper, plastic, metal — which makes it the right choice for packaging and printing.
Can the 12 mm gap be made wider?
The standard fork opening is 12 mm. If your target needs more clearance, tell us the dimension and line speed and we will confirm what we can build.
Need a quote for the Fork Sensor (U-Shaped Photoelectric)?
Send us your application — target material, sensing distance, supply voltage and housing constraint. We will recommend a part, quote it, and ship from Mumbai.