Monitoring heat flux sensor HF02

Overview
HF02 is a sensor that measures radiant heat flux or thermal radiation in the outdoor environment. A common application is monitoring the radiation emitted by flares. HF02 is certified for use in potentially explosive atmospheres, and is rated for radiation levels up to 15 x 103 W/m2. We recommend the use of HF02 in a decision-supporting role only, and not to use measurements of HF02 as the main or sole source of information for judging safety.

Key features
• Certified for explosive atmospheres: Supplied with an EC-type examination certificate specifying ATEX rating II 2G Ex db IIC T6 for installation in hazardous areas.
• Effective outdoor radiation and rain screening: Integrated radiation shields, rain screens, and cooling fins minimize solar heating and reduce wind/rain cooling effects, preventing false readings of a safe condition.
• Dual measurand capability: Features an open thermopile to detect radiant heat flux alongside a Type KX thermocouple that monitors sensor body temperature for redundant safety.
• Representative exposure measurement: The windowless open-detector design experiences convective wind cooling similar to human skin or exposed equipment, reflecting realistic field conditions.
• High environmental durability: Built with IP68 protection on the sensor head and high-temperature metal cable, enduring process temperatures from -50 °C to +300 °C.
• Easy integration: Generates a direct millivolt signal compatible with standard industrial data loggers and safety control systems.

Applications
• Flare radiation monitoring and outdoor flare boundary surveillance.
• Industrial alarm and safety systems for thermal radiation exposure of personnel and equipment.
• Monitoring thermal radiation in oil, gas, and petrochemical facilities located in potentially explosive zones.
• Outdoor perimeter heat flux monitoring near industrial burners and combustors.

Specifications
• Measurands: Radiant heat flux [W/m²] and sensor body temperature [°C]
• Sensor technology: Heat flux thermopile and thermocouple type KX
• Measurement range: 0 to 15 x 10³ W/m²
• Temperature measurement range: -30 to +100 °C
• Sensitivity (nominal): 0.3 x 10⁻⁶ V/(W/m²)
• ATEX rating: II 2G Ex db IIC T6
• Electrical data: Umax = 5 V, Imax = 5 x 10⁻³ A
• Rated process temperature range (sensor & metal cable): -50 to +300 °C
• Rated operating temperature range (transition piece & extension cable): -20 to +70 °C
• IP protection class:
– Sensor and high-temperature cable: IP68
– Low-temperature extension cable: IP67
• Standard cable lengths: 3 m high-temperature metal-sheathed cable and 3 m low-temperature extension cable
• Mounting dimensions: 3/8 UNC mounting holes

Cable length and other options
• Standard 3 m high-temperature metal-sheathed cable (extendable up to 100 m)
• Standard 3 m low-temperature extension cable (extendable up to 100 m)
• Dedicated signal converters for standardized output (such as 4-20 mA or voltage)
• Cable shielding options: standard connected shield or optional shield isolated from the high-temperature metal cable and body
• Verification by portable reference sensor (model HF03)