Today, Wuxi Rihuan Sensing Technology Co., Ltd. will introduce to you the "slot width" selection for slot-type photoelectric sensors - what are the appropriate widths for 5mm, 15mm, and 30mm? And where are they used?

The slot-type photoelectric sensor (also known as U-shaped photoelectric switch) has the transmitter and receiver encapsulated on both sides of the slot in the same housing. When the measured object passes through the slot and blocks the light path, it triggers the signal. Compared to the split-type beam photoelectric sensor, it has a compact structure and strong anti-interference ability. The slot width between the transmitter and the receiver directly determines the maximum size of the object that can pass through.

The core principle of selection is only one: the slot width must be larger than the maximum size of the detected object and leave sufficient margin - otherwise, the object cannot pass freely through the slot and may damage the internal structure of the sensor.

The common slot width specifications currently available on the market are mainly 5mm, 15mm, and 30mm. The following will explain each one in detail.

1. 5mm slot width: The "precise ruler" for detecting small parts

The 5mm slot width is suitable for detecting thin sheets, small objects, or precision components with a thickness of 5mm or less.

Typical application scenarios:

Electronic manufacturing: Chip pin detection, position detection and loading of material trays and belts, and counting

Precision machinery: Presence detection, counting, and position positioning of micro components

Automation systems: Limiting and positioning of sliding guides and linear modules, blade counting, and rotation disc positioning detection

Office and consumer equipment: Paper currency counting in point-of-sale machines, paper detection in printers

The sensor with a 5mm slot width is small in size and suitable for installation in equipment with limited space. Some high-end models can detect the smallest 0.8×1.8mm micro objects with an accuracy of below 0.03mm.

Selection reminder: The thickness of the detected object should be significantly less than 5mm and leave sufficient clearance to avoid the object getting stuck in the slot or scratching the inner wall of the sensor.

2. 15mm slot width: The "main force" for general automation

The 15mm slot width is the most commonly used medium-sized specification in industrial automation, suitable for medium-sized workpiece positioning detection and widely used in various conventional automation scenarios.

Typical application scenarios:

Mechanical arm positioning: Precisely capturing the position of the workpiece to assist in precise operation and precise positioning of the workpiece

Packaging and logistics: Product detection in packaging machinery, package passing status detection in logistics sorting systems

Elevator and conveying equipment: Elevator leveling control, object positioning on conveyor belts

Automotive parts: Automotive part positioning detection

The 15mm slot width provides a larger through space than 5mm, can accommodate larger workpieces, and the sensor itself has a moderate volume, making installation flexible.

Selection reminder: The thickness of the detected object should be within 15mm. If the object size is close to 15mm, it is recommended to choose a larger slot width or leave a margin to avoid jamming due to fluctuations in object size or installation errors.

3. 30mm slot width: The "passenger" for large workpieces

The 30mm slot width is a large slot width specification, suitable for large-sized workpiece through detection, and is applicable to detection scenarios for large components, plates, etc.

Typical application scenarios:

Large workpiece detection: 30mm or less workpiece presence or position detection on automated equipment

Tool and gear detection: Tool breakage detection, gear speed measurement, label detection

Position control and edge detection: Fixture position control, workpiece ejection, tray transfer

Food and packaging machinery: Marking and color marking detection in food, medicine, packaging, and printing machinery

Some 30mm slot width products use a sturdy metal housing, with a maximum response time of up to 20 microseconds and a detection accuracy of up to 0.1mm.

Selection reminder: The thickness of the detected object should be within 30mm.

Selection summary

Slot width Applicable object size Typical scenarios

5mm Thickness ≤ 5mm Electronic components, small part counting, precision positioning, paper detection

15mm Thickness ≤ 15mm Mechanical arm positioning, packaging logistics, automotive components, elevator leveling

30mm Thickness ≤ 30mm Large workpieces, tool fracture detection, gear speed measurement, sheet material detection

The Rihuan Sensor provides three slot types of 5mm, 15mm, and 30mm for slot-type photoelectric sensors. These cover various scenarios such as small part counting, mid-sized workpiece positioning, and large workpiece passage detection. The product adopts an integrated infrared beam design. It is precisely aligned before leaving the factory and can be used immediately after power-on, without the need for on-site debugging. Welcome to follow Rihuan Sensor to obtain professional slot-type photoelectric sensor selection guidance and technical support.