RD24-4S Doppler Detector | 4m×2m Wide Detection Field, High Precision Motion Sensing
The RD24-4S Doppler Detector is a professional high-performance motion sensing device built for heavy-duty commercial access and automatic door systems, featuring a 4m×2m wide detection field and industry-leading high precision motion sensing, making it the top choice for large-entry commercial spaces, office lobbies, shopping malls and retail outlets. Powered by mature 24.125GHz microwave Doppler technology, this detector delivers an expansive 4-meter width and 2-meter depth detection range at the standard 2.2m mounting height, fully covering large commercial entryways and wide sliding glass door passages without dead zones, ensuring every approaching pedestrian is accurately captured. Its high-precision sensing core excels at identifying subtle human movement at a minimum speed of 5cm/s, with an intelligent algorithm that strictly filters out false triggers from environmental vibrations, floating debris and non-human motion, eliminating frequent door malfunctions caused by misdetection.
Unlike ordinary detectors with narrow or unstable sensing ranges, this model balances wide coverage and precise targeting, adapting to various installation positions and door types without repeated calibration. Encased in a sturdy ABS housing, it features stable performance in complex electromagnetic environments, resists daily wear and tear, and complies with R&TTE and EMC international certifications for safe, interference-free operation. With plug-and-play compatibility and consistent signal output, it seamlessly integrates with mainstream automatic door control systems, requiring no complex setup. Combining a generous wide detection field and ultra-high precision, this Doppler detector stands as a reliable, long-lasting solution for commercial-grade motion sensing needs.


Product Highlights
- 24.125GHz mainstream microwave frequency for stable motion detection (≥5cm/s)
- Wide detection field: 4m(W)*2m(D) at 2.2m mounting height
- Flexible angle adjustment: 0°~90° vertical / -30°~+30° lateral tilt
- Wide voltage supply: 12-24V AC/DC with low power consumption (≤2W)
- IP54 protection & -20℃~+55℃ working temperature for indoor/outdoor semi-enclosed use
- Easy installation & adjustment with compact size, sensitivity potentiometer, and clear LED status prompt
- Reliable output: 1.5s signal hold, 42V AC/DC max contact voltage, 1A resistive current
Technical Specifications
| Parameter |
Specification |
| Technology |
Microwave Doppler Radar |
| Transmitter Frequency |
24.125GHz |
| Transmitter Radiated Power |
<20 dBm EIRP |
| Transmitter Power Density |
≤5mW/cm |
| Maximum Mounting Height |
3m |
| Tilt Angles |
0°~90° vertical; -30°~+30° lateral |
| Detection Field (2.2m mounting) |
4m(W)*2m(D) |
| Detection Mode |
Motion detection |
| Minimum Detectable Speed |
5cm/s (sensor axis) |
| Supply Voltage |
12-24V AC ±10%; 12-24V DC +30% / -10% |
| Mains Frequency |
50-60Hz |
| Power Consumption |
≤2W(VA) |
| Output Mode |
Switch tube output |
| Signal Output Time |
1.5s hold |
| Max Contact Voltage |
42V AC/DC |
| Max Contact Current |
1A (resistive) |
| Max Switching Power |
30W(DC) / 60VA(AC) |
| Working Temperature Range |
-20℃ ~ +55℃ |
| Degree of Protection |
IP54 |
| Norm Conformity |
R&TTE 1999/5/EC; EMC 89/336/EEC |
| Material |
ABS |
| Housing Color |
Black/Silver |
| Dimensions (W*H*D) |
120mm*80mm*50mm |
| Net Weight |
0.215kg |
| Cable Length |
2.2m |
Installation & Adjustment Guide
The sensor's performance is closely related to correct installation and adjustment. Simple operation with no professional tools required:
Mounting Requirements
Avoid vibration positions, neon lamp proximity and sensor occlusion; do not touch internal electronic parts during installation.
Sensitivity Adjustment
Rotate the sensitivity potentiometer gently and slowly; the sensitivity value determines the size of the detection field (adjust to 1/2 or higher for short detection distance).
Angle Adjustment
Planar antenna lateral angle = detection field position; vertical angle = detection field depth; set microwave module angle to ≥45° for optimal detection.
Status Check
LED flashes after power-on (normal standby); LED lights up continuously when a moving target is detected (detection trigger).
Troubleshooting Guide
| Fault Phenomenon |
Probable Causes |
Corrective Action |
| Door does not open & LED no light |
Sensor power off |
Check wiring connection and power supply validity |
| Door opens/closes constantly |
Sensor detects door vibration/movement; interference source in detection range |
Fix the sensor firmly; increase tilt angle/reduce sensitivity; remove interference sources in the detection field |
| Detection distance is too close |
Low sensitivity; microwave module angle <45°; sensor blocked |
Adjust sensitivity potentiometer to 1/2 or higher; set module angle to ≥45°; remove occluding objects |
Application Scenarios
The RD24-4S is a multi-scenario motion detection sensor with high adaptability, primarily applicable to:
- Automatic Door Systems: Sliding doors, swing doors, glass induction doors (commercial buildings, shopping malls, office buildings)
- Security & Monitoring: Perimeter security detection, indoor human motion induction (residential, factory, warehouse)
- Industrial Automation: Conveyor belt motion detection, equipment start/stop induction (light industry production lines)
- Intelligent Building: Smart lighting induction, air conditioning induction (public areas such as corridors and elevators)
Core Technologies
Microwave Doppler Radar Sensor 24.125GHz Radar Sensor Automatic Door Motion Detector Wide Field Detection Sensor IP54 Motion Sensor