1. Product Overview
The INK462 Integrated Tunnel Four-Gas Visibility Detector is a comprehensive, continuous monitoring instrument designed for road, railway, and industrial tunnel applications. It collects real-time data on visibility (VI), carbon monoxide (CO), carbon dioxide (CO₂), nitric oxide (NO), nitrogen dioxide (NO₂), hydrogen sulfide (H₂S), methane (CH₄), temperature, and humidity. This multi-parameter data enables traffic management authorities to optimize ventilation systems, maintain safe air quality levels, and ensure reliable road operations. The detector combines high-performance imported sensors with a rugged, sealed design, delivering long-term stability and minimal maintenance in corrosive, high-humidity tunnel conditions.
2. Sensing Technology & Self-Cleaning System
The INK462 uses a hybrid of proven sensing technologies tailored for tunnel environments:
- Gas Sensing: CO, CO₂, NO, NO₂, H₂S, and CH₄ are measured using electrochemical and infrared (IR) principles. Electrochemical sensors deliver high accuracy for toxic gases, while IR-based sensors provide stable, drift-resistant readings for CO₂ and CH₄.
- Visibility Monitoring: The unit uses infrared scatter technology, where an infrared light source is projected across the tunnel air path. Airborne particles scatter the light, and the sensor calculates visibility (VI) based on scattered light intensity. The design is fully immune to stray tunnel lighting, ensuring consistent, reliable measurements.
- Temperature & Humidity Sensing: Band-gap and capacitive measurement principles provide precise readings in variable, non-condensing humidity conditions.
- Environmental Adaptation & Maintenance: While the detector does not include an active self-cleaning mechanism, its IP68-rated fully sealed enclosure prevents dust, moisture, and corrosive tunnel gases from damaging internal components. Built-in real-time diagnostics provide fault display, status indication, and signal verification, simplifying maintenance and reducing downtime in hard-to-access tunnel locations.
3. Key Features & Competitive Advantages
- All-in-One Multi-Parameter Design: Eliminates the need for multiple separate sensors by combining visibility, six gases, temperature, and humidity monitoring into a single unit, reducing installation complexity, cabling costs, and integration effort.
- High-Performance Imported Sensors: Delivers exceptional accuracy, repeatability, and long-term stability, with a minimum operating life of 50,000 hours for reduced replacement and maintenance costs.
- Stray Light Immunity: The visibility measurement system is completely unaffected by variable tunnel lighting conditions, ensuring reliable data regardless of tunnel illumination levels.
- 32-Bit Ultra-Low-Power Processor: Provides fast response times, stable operation, and a touchscreen display for easy configuration, calibration, and on-site monitoring.
- IP68 Protection Rating: Fully sealed against dust, water, and corrosive tunnel environments, enabling reliable operation in harsh, high-humidity conditions.
- Flexible, Expandable Configuration: Optional extended ranges for gases, temperature, and humidity allow customization to meet the specific requirements of different tunnel types (e.g., road, railway, mining).
- Multi-Channel Industrial Outputs: Supports 7-channel isolated 4-20 mA analog outputs, RS232/RS485/RS422 digital interfaces, 10M/100M Ethernet, and 8-channel relay outputs, enabling seamless integration with tunnel SCADA, ventilation control systems, and traffic management platforms.
- Built-In Diagnostics: Real-time fault display, status indication, and signal verification enable proactive maintenance, reducing unplanned downtime and improving operational safety.
4. Technical Specifications
| Parameter |
Specification |
| Visibility (VI) Range |
0 ~ 15 1/km; 0 ~ 35 1/km (optional) |
| CO Range |
0 ~ 300 ppm; 0 ~ 600 ppm (optional) |
| CO₂ Range |
0 ~ 5000 ppm (optional) |
| NO Range |
0 ~ 50 ppm (optional) |
| NO₂ Range |
0 ~ 10 ppm (optional) |
| H₂S Range |
0 ~ 100 ppm (optional) |
| CH₄ Range |
0 ~ 100 % LEL (optional) |
| Temperature Range |
-40 °C ~ +70 °C (optional) |
| Humidity Range |
0 ~ 100 % RH (optional, non-condensing) |
| Visibility (VI) Accuracy |
±0.1 1/km |
| CO Accuracy |
±1 ppm |
| NO Accuracy |
±0.1 ppm |
| NO₂ Accuracy |
±0.04 ppm |
| Operating Temperature |
-50 °C ~ +75 °C |
| Operating Humidity |
0 ~ 100 % RH, non-condensing |
| Power Supply |
AC 220 V / DC 12 V |
| Operating Life |
≥50,000 hours |
| Protection Class |
IP68 |
| Data Storage |
Local TF card, expandable to 32 GB |
| Power Consumption |
Max 70 W; rated 30 W |
| Analog Output |
7-channel isolated 4 ~ 20 mA; load impedance 750 Ω |
| Digital Interface |
RS232/RS485/RS422; 10M/100M adaptive RJ45 |
| Relay Output |
8-channel SPCO switch outputs |
5. Applications
- Road tunnel environmental monitoring for ventilation control and traffic safety alerts
- Urban highway and underpass air quality monitoring for emissions management
- Railway tunnel safety monitoring for toxic gases and low-visibility conditions
- Underground mining tunnel gas detection for explosion prevention and worker safety
- Industrial utility tunnel environmental monitoring for operational compliance
- Smart city tunnel management systems for automated ventilation and safety control
- Emergency response tunnel monitoring for disaster and rescue operations
- Toll plaza and low-visibility traffic environment air quality and visibility tracking
