Datalogic SR21 / SRX Fork Sensor for Label Detection
The small fork sensors that tell a labeller exactly where each label starts.
The Datalogic SR21 is a high-resolution optical fork sensor with a 2 mm slot and 50 mm depth, fast enough for high-speed label dispensing. Choose SR21-IR for labels on transparent liner or SR21-RG for printed marks. For fully transparent labels, the ultrasonic SRX3 fork sensor is the answer.
SR21-IR, SR21-RG and SRX3
| Feature | SR21-IR | SR21-RG | SRX3 (ultrasonic) |
|---|---|---|---|
| Principle | Infrared LED 880 nm | Red/green LED 633/570 nm | Ultrasonic |
| Best for | Labels on transparent film | Print register marks | Clear-on-clear and metallised labels |
| Slot | 2 × 50 mm | 2 × 50 mm | 3 mm slot (e.g. 3 × 68 mm) |
| Speed | 20 µs, 25 kHz | 20 µs, 25 kHz | Model dependent |
| Output | NPN and PNP | NPN and PNP | PNP/NPN versions |
| Connection | M8 4-pin | M8 4-pin | M8 or M12 |
| Protection | IP65 | IP65 | Model dependent |
SR21 data from the Datalogic SR21 catalogue; SRX3 from Datasensing model listings.
Setting Up an SR21
- Thread the web centrally. The label web should pass through the middle of the 2 mm slot without touching the arms.
- Static teach. Place the liner (gap) in the slot, press AUTO-SET, then place a label and press again.
- Dynamic teach. Or hold AUTO-SET while the web runs; the sensor learns labels and gaps automatically.
- Check the gap signal. Confirm the output switches on every gap at full dispensing speed.
Fork Sensor Models in Stock
| Model | Key details | Price (excl. GST) |
|---|---|---|
| Datalogic SR21-RG | Fork / label · RGB / red-green LED · M8 | Rs. 15,895 |
| Datalogic SR21-IR | Fork / label · Infrared LED | Rs. 8,690 |
All SR21 models above are listed on Industrypapa with a GST invoice. Prices are indicative and may change; ask us for bulk or project pricing.
SRX3 ultrasonic fork sensors are supplied on request.
SR21 Sensors in Stock
SR21 / SRX FAQs
What is the difference between SR21-IR and SR21-RG?
SR21-IR uses infrared light for labels on transparent liners; SR21-RG uses red/green light to read printed marks.
Can the SR21 detect transparent labels?
Not reliably when both label and liner are clear — use the ultrasonic SRX3 for clear-on-clear labels.
How small an object can the SR21 detect?
About 0.5 mm with its 2 mm slot.
What is the SR21 price in India?
SR21 models on Industrypapa start from about Rs. 8,690 (excl. GST).
Do you supply genuine Datalogic sensors with GST invoice?
Yes. Industrypapa supplies genuine Datalogic (Datasensing) sensors with a proper GST invoice, and in-stock models are dispatched the same day from Noida.
Can you deliver outside Delhi NCR?
Yes. We ship across India and export to 220+ countries through DHL, ARAMEX and FedEx with tracking.
Get a Fork Sensor Quote
Tell us the label type (paper, clear, metallised), liner and machine speed. We will recommend SR21 or SRX and quote.
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F412 (4th floor), Plot No-21, Arthamart, Techzone-4, Noida Extension, UP — 201318
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