1. Product Overview
The INK450 Tunnel CO & Visibility Detector is a specialized environmental monitoring device designed for road tunnel applications. It continuously collects visibility (VI) and carbon monoxide (CO) data in real time, providing traffic authorities with reliable insights to manage tunnel ventilation and ensure safe passage. Tunnels, being confined spaces, face risks from exhaust accumulation and reduced visibility, which can lead to accidents. This detector enables timely forced ventilation and safety interventions, making it a critical component for tunnel safety systems. It is built for long-term, maintenance-free operation in harsh tunnel environments.
2. Sensing Technology & Self-Cleaning System
Sensing Technology:
The INK450 uses the light transmission method with a 940 nm light source for visibility measurement. It projects light across a 6-meter optical path (with probes installed 3 meters apart), and measures light attenuation caused by dust, smoke, or fog to calculate visibility levels in 1/m units. For carbon monoxide (CO), it employs electrochemical sensing to detect gas concentration in ppm. The system is engineered to be immune to stray light sources, ensuring high-resolution, accurate readings even in variable tunnel lighting conditions. It also supports optional expandable nitrogen oxide (NOₓ) detection via additional electrochemical sensors.
Self-Cleaning & Maintenance Design:
While no explicit self-cleaning mechanism is detailed, the device’s rugged construction and vibration-resistant design prevent measurement failures caused by environmental factors. Its maintenance-free operation minimizes upkeep needs in hard-to-reach tunnel locations, with no routine calibration required beyond periodic visual inspections.
3. Key Features & Competitive Advantages
- Dual-Parameter Monitoring: Simultaneously measures visibility and CO, eliminating the need for separate sensors and reducing installation complexity.
- Stray Light Immunity: High-resolution visibility measurement remains unaffected by ambient light sources, ensuring consistent accuracy in dynamic tunnel environments.
- Expandable Gas Detection: Optional NOₓ measurement capability allows adaptation to evolving tunnel emission monitoring requirements.
- Vibration-Resistant Build: Rugged construction resists vibration-induced measurement errors, critical for tunnels with heavy traffic.
- Multiple Output Options: Supports RS485 digital communication and 4–20 mA analog outputs, enabling seamless integration with SCADA and ventilation control systems.
- Low Maintenance Operation: Designed for maintenance-free use, reducing long-term operational costs in remote tunnel deployments.
- Wide Environmental Tolerance: Operates reliably from -40 °C to +70 °C and 0–100 %RH, suitable for extreme tunnel conditions.
- Long MTBF: Mean Time Between Failures of ≥15,000 hours ensures high reliability for continuous, unattended monitoring.
4. Technical Specifications
| Parameter |
Specifications |
| Measured Parameters |
Visibility (VI), Carbon Monoxide (CO); NOₓ (Optional) |
| Measurement Units |
Visibility: 1/m; CO: ppm |
| Measurement Accuracy |
Visibility: ±0.0001 1/m; CO: ±1 ppm |
| Measurement Range |
Visibility: 0 ~ 35×10⁻³ 1/m; CO: 0 ~ 400 ppm |
| Measurement Method |
Light transmission (visibility); Electrochemical (CO/NOₓ) |
| Optical Path / Installation Distance |
6 m optical path (probe installation distance: 3 m) |
| Operating Temperature |
-40 °C ~ +70 °C |
| Operating Humidity |
0 ~ 100 %RH |
| Light Source Wavelength |
940 nm |
| Output Interval / Data Update |
60 s; 1 record/min |
| Power Supply |
AC 220 V / DC 12 V |
| Power Consumption |
≤10 W |
| Communication Interfaces |
RS485, 4 ~ 20 mA analog output |
| Reliability (MTBF) |
≥15,000 hours |
| Mounting |
Wall-mounted on tunnel sidewall |
5. Applications
- Road tunnel ventilation control and safety monitoring systems
- Highway tunnel traffic management and accident prevention
- Urban underground transportation infrastructure monitoring
- Railway tunnel environmental safety and emission control
- Industrial tunnels and mine access air quality monitoring
- Emergency response and fire safety systems in tunnels
- Compliance reporting for tunnel operational safety standards
- Integration with smart city traffic management platforms
