The Datalogic SRX3 Ultrasonic Fork Sensor detects transparent, opaque and metallic-ink labels in packaging, labelling and print-and-apply machinery, including clear labels on clear backing. Its ultrasonic sensing method distinguishes labels from their backing without relying on optical contrast and supports single- and double-film detection after application-specific setup.
SRX3 transmits ultrasound across its fork slot and detects changes in the signal as the label and backing pass through the sensing area. This allows it to distinguish the backing alone from the backing plus label, even when both materials are transparent.
The sensor suits label-feed and positioning tasks in bottle labellers, cosmetic packaging equipment, pharmaceutical labelling machines and print-and-apply systems. Detection takes place on the moving label web before dispensing, providing a switching signal for the machine controller.
The series supports paper, plastic and metallic labels on paper, plastic or metallic backing materials. Transparent labels and metallic-ink printing are relevant applications because detection does not depend on the colour contrast between the label and its liner.
Single- and double-clear-film checks, double-sheet detection and adhesive-surface detection are also listed applications. These require validation with representative samples: SRX3 detects a change between material conditions, rather than providing a calibrated thickness measurement or assessing adhesive strength.
The fork has a 3 mm slot width and 68 mm depth. The specified web width is greater than 16 mm, and the material must cover the marked sensing area. Keep the web taut and supported on the sensor’s guide during teaching and operation; clearance through the slot alone does not establish suitability.
SRX3 has a 1 ms response time, 500 Hz switching frequency and a specified maximum web speed of 60 m/min. The shortest label or gap affects the available detection time, so assess speed together with material dimensions and the controller’s input timing.
The technical data specifies detectable sizes greater than 2 mm. Detection at a 2 mm label gap is an application-dependent capability and should be checked using the actual label stock, backing and operating speed.
Where the material cannot pass through a fork, compare other industrial sensors suited to the required detection geometry.
Teach-in sets the switching threshold for the material being detected. SRX3 uses separate dynamic and static teach models, so choose the setup method when specifying the sensor.
Dynamic teaching begins with a label positioned in the fork, then uses several labels moving through the sensing area to establish the operating condition. Static teaching learns with a label held in position. Static versions also provide offset adjustment, which changes the switching threshold when further tuning is required.
Remote teach-in reproduces the setup input through machine wiring. It is available on the M12 PNH and M8 PH versions; M8 PN versions provide PNP and NPN outputs without remote teaching.
| Model | Teach-in | Connector | Outputs | Remote teach-in |
|---|---|---|---|---|
| SRX3-5-US-M12-PNH | Dynamic | M12, 5-pin | PNP and NPN | Yes |
| SRX3-5-US-3-M12-PNH | Static | M12, 5-pin | PNP and NPN | Yes |
| SRX3-6-US-M8-PH | Dynamic | M8, 4-pin | PNP | Yes |
| SRX3-6-US-3-M8-PH | Static | M8, 4-pin | PNP | Yes |
| SRX3-6-US-M8-PN | Dynamic | M8, 4-pin | PNP and NPN | No |
| SRX3-6-US-3-M8-PN | Static | M8, 4-pin | PNP and NPN | No |
SRX3 requires a 12–30 V DC supply and supports an output current up to 250 mA. Match the output to the controller input: PNP supplies current to the input, while NPN switches it towards 0 V. Confirm the exact pin assignment before reusing an existing cable, particularly when changing between M8 PH and PN versions.
The aluminium housing measures approximately 90 × 55 × 22 mm. Allow space for the connector, cable bend and material guide as well as the sensor body. Specify a matching M8 4-pin or M12 5-pin cable, including its required length and connector orientation.
Operating limits are 0–50°C and 35–85% relative humidity without condensation. IP54 protection suits installations exposed to limited dust and splashing; applications involving washdown jets or immersion require different protection. SRX3 is a process sensor and is not suitable for personnel-protection functions.
For a machine using clear labels on clear backing, a PNP controller input and an M12 connection, the SRX3-5-US-M12-PNH provides dynamic teaching and a remote setup input. Teaching starts with a label at the sensing point, continues with several labels moving through the fork and finishes by saving the setting. Commissioning should then check individual label and gap transitions at the intended production speed, including the controller’s input filtering.
For opaque or booklet labels that provide sufficient optical contrast, the Datalogic SR23 fork sensor is a relevant alternative. It uses infrared light, has a 5 mm slot width and 50 mm depth, and specifies a 40 µs response time, compared with SRX3’s 3 mm slot width, 68 mm depth and 1 ms response time.
SR23’s faster response and wider slot may favour optically distinguishable or thicker label stock. SRX3 addresses clear-on-clear materials where optical separation is difficult. Select using the actual label and backing combination; response time alone does not determine achievable web speed.
MarvelTech can review the label material, backing, web speed and control requirements to help select an SRX3 configuration. For a replacement, include the existing sensor model and wiring details so connector fit, output type and teaching requirements can be checked together.
Send representative label or film samples, web width, label length, gap size, maximum operating speed and installation photos. Specify the supply voltage, controller input type, connector, teaching preference, remote-teach requirement and quantity.
Request a quote for the selected sensor and required cables, identifying any installation or setup support needed. Ask MarvelTech to confirm availability, lead time, applicable warranty terms and support at your installation location.
Yes. SRX3 uses ultrasound to distinguish the backing alone from the backing plus label, including clear-on-clear combinations. It also supports opaque labels and metallic-ink printing without relying on optical contrast. Selection still depends on the complete label construction: assess representative samples with their actual backing, adhesive and printing, particularly when one machine handles several label formats.
Choose SRX3 when transparent labels and backing provide insufficient optical contrast. The Datalogic SR23 optical fork sensor is an alternative for optically distinguishable labels, including booklet formats requiring its wider 5 mm slot. SRX3 has a 3 mm slot. Compare material response, total label thickness and timing requirements before considering either sensor as a replacement.
The technical data specifies detectable sizes greater than 2 mm, a 1 ms response time, 500 Hz switching frequency and a maximum web speed of 60 m/min. Assess these limits together: short gaps at high speed produce brief signals. Detection at a 2 mm gap requires application validation; check the actual label stock and the controller’s input filtering at the intended production speed.
SRX3 has a 3 mm slot width and 68 mm slot depth, with a specified web width greater than 16 mm. The material must cover the marked sensing area and remain taut against the guide during setup and operation. Check clearance for the complete label-and-backing thickness, splices and web movement, together with mounting access and connector space.
Dynamic models learn while several labels move through the sensing area; static models learn with a label held in position. These are separate sensor variants, so select the teaching method before ordering. For example, SRX3-5-US-M12-PNH uses dynamic teaching, while SRX3-5-US-3-M12-PNH uses static teaching. Choose according to whether the machine can move the label web during setup.
M12-PNH versions provide both PNP and NPN outputs plus remote teach-in. M8-PH versions provide a PNP output plus remote teach-in, while M8-PN versions provide both PNP and NPN outputs without remote teaching. Each configuration is available with static or dynamic teaching. An NPN installation requiring remote setup therefore needs the M12-PNH configuration within this range.
SRX3 requires a 12–30 V DC supply, a compatible PNP or NPN controller input and a matching M8 four-pin or M12 five-pin cable. Its specified maximum output current is 250 mA. Setup uses teach-in controls rather than PC software. Confirm cable length, connector orientation and pin assignments, especially when changing between M8 versions with different output and remote-teach functions.
Yes. Double-sheet, clear-film and adhesive-surface detection are supported application types, subject to teaching and material assessment. SRX3 provides a switching result based on differences in ultrasonic transmission; it does not provide a calibrated thickness reading or measure adhesive strength. Supply samples representing each condition the machine must distinguish, including acceptable material and the fault condition.
SRX3 has an IP54 enclosure and operating limits of 0–50°C with 35–85% relative humidity without condensation. These limits suit protected machine installations, but IP54 does not establish suitability for pressure washing or immersion. For food or pharmaceutical machinery, assess the sensor’s actual mounting position, cleaning exposure and condensation risk before selecting it.
No. SRX3 detects material transitions as the label web passes through its fork before dispensing. Its switching signal supports label-feed control but does not read printed information or inspect the applied label. If the requirement includes checking text, orientation or placement on a container, assess a separate machine vision inspection system around those inspection criteria.
Provide label and backing samples, web width, total thickness, smallest label and gap dimensions, and maximum operating speed. Include the PLC input type, supply voltage, connector preference, teaching method and remote-teach requirement. For replacements, add the existing part number and wiring details. Use the SRX3 order enquiry form to request the sensor, required cables, quantity and any installation support, with availability and lead time confirmed in the quotation.
The Datalogic SRF Fork Sensor is a photoelectric fork sensor for small-part detection, edge positioning and object counting in packaging machinery, automotive assembly and automated production lines. Four fork widths, from 30 to 120 mm, and separate LED and laser models allow selection according to the available clearance, target size and switching-speed requirement.
See DetailsThe Datalogic SR23 Fork Sensor is a photoelectric label sensor for label-edge and gap detection in labelling machines, packaging lines and print-and-apply systems. Its 5 mm fork slot accommodates booklet and multilayer label formats, while a switching frequency of up to 12 kHz supports fast label-feed control.
See DetailsThe Datalogic SR21 Fork Sensor is a photoelectric label sensor for label positioning and print register-mark detection in packaging, labelling and print-and-apply machinery. With a maximum response time of 20 µs and switching frequency up to 25 kHz, it provides fast detection signals as material passes through its 2 mm fork slot.
See DetailsPlease contact us if you have any questions or comments.
