Cooled heat flux sensors - CHF Series
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CHF Series sensors are available with two standard mechanical interfaces (screw-mount or flange-mount) and can also be customized to specific requirements.
CHF probes are cooled via an optimized internal structure (heat exchanger) supplied either by tap water (once-through cooling) or by a circulating thermostatic bath (chiller/circulator). In both cases, connections are made via two barbed fittings. The internal heat exchanger ensures the sensor's rear face is precisely maintained at a set temperature, even under the highest heat fluxes (>MW/m²). The cooling hoses feature quick-connect fittings for easy assembly and disassembly of the circuit.
Like all NexTherm Sensing sensors, the CHF Series heat flux sensors are designed for robustness, reliability, and durability. Notably, they stand out from the competition due to their unique ability to operate under vacuum or high-pressure conditions.
Product details
CHF sensors are designed for the direct, real-time measurement of heat fluxes ranging from moderate (tens of kW/m²) to high (several MW/m²) over extended periods, including for continuous monitoring applications. Complementing the IHF and GHF series, CHF heat flux sensors feature an optimized cooling system integrated directly into the sensor body. Delivering a voltage output (millivolts) proportional to the incident flux, CHF sensors operate reliably in the harshest environments while maintaining outstanding performance, including rapid response times (<200 ms) and high sensitivity (several mV per MW/m²).
CHF sensors provide continuous, instantaneous heat flux measurements up to several MW/m². They are an excellent choice for industrial thermal monitoring and for applications where uncooled sensors reach their operational limits.
Four full-scale flux ranges are available: 250, 500, 1,000 (= 1 MW/m²), and 5,000 kW/m² (= 5 MW/m²).
CHF sensors are available in total, radiative, or convective heat flux versions. In the convective version, the sensor's sensing element features a reflective surface coating (mirror-polished gold). Conversely, in the total version, the sensing element is coated with an absorbent black layer; its emissivity—close to 1—has been measured in the laboratory across a broad spectrum. As for the radiative version, the coating is similar to that of the total version, but the sensor is equipped with a glass window (sapphire or other materials available upon request) to eliminate convective effects.
