BRQ diffuse reflective front-sensing sensors are one-body photoelectric sensors that detect targets using light reflected directly from the object. The BRQ front-sensing lineup includes 100 mm, 400 mm, and 1 m diffuse reflective models, along with cable and connector options, NPN and PNP outputs, multiple body materials, and sensitivity adjustment. These variants are well suited to compact machine layouts where a reflector or separate receiver is impractical.

What Is It

A diffuse reflective photoelectric sensor is a self-contained optical sensor that both emits and receives light within one housing. Instead of relying on a second device or reflector, it detects the target directly from reflected light returning from the target surface. That makes installation fast and mechanically simple, which is why diffuse reflective sensors are common in short-range industrial automation tasks. The tradeoff is that performance is more dependent on target reflectivity, finish, size, and environmental reflections. The technical overview explicitly notes that reflective sensing distance varies with the change in received-light intensity caused by target characteristics.

Working Principle

The sensor projects light toward the target. When enough reflected light returns to the receiving element, the output changes state according to the configured operation mode. In BRQ reflective models, light ON and dark ON can be selected by control-wire connection. Because direct return intensity matters, dark matte targets, glossy backgrounds, and environmental reflections can all change real-world sensing margin. That is why model choice and sensitivity setting matter more in diffuse sensing than many users expect.

Types / Variants

BRQ front-sensing diffuse reflective models are specified at:

• 100 mm
• 400 mm
• 1 m

Variants include:

• Plastic, brass Ni-plated, and SUS316L materials
• Cable or connector versions
• NPN or PNP outputs
• Standard body, with short-body plastic variants within the wider family structure.

Key Specifications

Relevant published data includes:

• Sensing distance: 100 mm / 400 mm / 1 m
• Sensing target: opaque, translucent materials
• Hysteresis: ≤ 20% of sensing distance
• Response time: ≤ 1 ms
• Power supply: 10–30 VDC ±10%
• Reflective current consumption: ≤ 30 mA
• Operation mode: Light ON / Dark ON selectable by control wire
• Protection rating: IP67, and IP69K for SUS316L versions.

Applications

BRQ diffuse reflective sensors are well suited to:

• Short conveyor presence checks
• Small machine stations
• Product count confirmation
• Object-in-position sensing
• Packaging presence sensing
• Direct target detection where reflector mounting is impractical
• Compact automation layouts where a one-body sensor is preferred.

Selection Guide

Choose BRQ diffuse reflective when:

• Installation space is tight
• Only one sensor body can be installed
• Target distance fits within 100 mm, 400 mm, or 1 m classes
• The target has reasonably predictable reflective behavior
• Wiring simplicity matters more than the extra margin of through-beam.

Pick the shortest model that gives adequate application margin. Shorter-range diffuse models can be more stable than overextending a longer-range model into a reflective environment with strong background influence.

Common Mistakes

• Using diffuse reflective sensing on very dark or inconsistent targets without testing
• Ignoring glossy background reflections
• Mounting too close to surrounding metal or bright machine surfaces
• Overestimating rated distance without considering target reflectivity
• Skipping sensitivity optimization
• Using diffuse sensing where through-beam or polarized retroreflective is the better fit.

Troubleshooting

If the sensor sees the background instead of the product:

• Increase target/background separation
• Darken or reduce reflective backgrounds
• Reposition the sensor angle
• Reduce sensing distance
• Re-adjust sensitivity
• Reassess whether diffuse sensing is appropriate for the target.

If the sensor misses dark products:

• Test at shorter range
• Check target size
• Increase sensing margin
• Move to through-beam if reflectivity is too low for stable diffuse operation.

FAQs

What ranges are available in BRQ diffuse reflective models?
100 mm, 400 mm, and 1 m.

Can diffuse reflective models detect translucent materials?
Yes. The specification table states opaque and translucent materials.

Are diffuse reflective sensors more affected by target color?
Yes. The technical overview explicitly notes reflective sensing depends on returned light intensity and target characteristics such as size, color, and material.

Can I get NPN and PNP versions?
Yes. NPN and PNP open-collector variants are supported.

Related Products / Internal Links

• BRQ Diffuse Reflective Products on Smidmart
• Compact Photoelectric Sensors
• Sensor Cables and Connectors
• Object Detection Sensors for Conveyors