Posted in | Heat Flux Sensors

Heat Flux Sensors for All Applications - FHF05 series

If your goal is to measure heat flux, the FHF05 series heat flux sensors is the way to go. It offers models in five dimensions and sensitivities, ensuring flexibility to meet diverse requirements. All FHF05 models come with integrated temperature sensors and thermal spreaders, reducing dependence on thermal conductivity. They operate effectively within a temperature range of -70 to +120 °C, measuring heat flux from conduction, radiation, and convection.

Additionally, users can choose between black (BLK) and gold (GLD) stickers for all five models, allowing for the separate determination of heat transport by radiation and convection. If the FHF05 series does not align with your specific needs, there are other specialized heat flux sensor models available for consideration. Contact us to discuss your needs.

Heat Flux Sensors for All Applications

Image Credit: Hukseflux Thermal Sensors B.V.


Source: Hukseflux Thermal Sensors B.V.

. .
Measurand heat flux, temperature
Outer dimensions foil with guard (10 x 10, 15 x 30, 50 x 50, 15 x 85, 85 x 85) x 10⁻³ m
Measurement range (-10 to +10) x 10³ W/m²
Sensitivity (nominal) :
FHF05-10X10 1 x 10⁻⁶ V/(W/m²)
FHF05-15X30 3 x 10⁻⁶ V/(W/m²)
FHF05-50X50 13 x 10⁻⁶ V/(W/m²)
FHF05-15X85 7 x 10⁻⁶ V/(W/m²)
FHF05-85X85 50 x 10⁻⁶ V/(W/m²)
Temperature sensor type T thermocouple*
Thermal spreaders included
Rated bending radius ≥ 7.5 x 10⁻³ m
Rated load on cable ≤ 1.6 kg
Sensor thermal resistance 11 x 10⁻⁴ K/(W/m²)
Sensor thickness 0.4 x 10⁻³ m
Uncertainty of calibration ± 5 % (k = 2)
Rated temperature range - continuous use -70 to +120 °C
Rated temperature range - short intervals -160 to +150 °C**
IP protection class IP67***
Standard wire length 2 m
Options without wiring, without connection block; with 5 m wire length; with 10 m wire length; with BLK-black and/or GLD-gold stickers for every dimension
* temperature measurement uncertainty: 2 % of value in °C. For details, refer to user manual
** when measuring at temperatures of -160 °C , contact Hukseflux.
*** sensor is not suitable for continuous exposure to water



  • BLK sticker for all models (to measure radiative as well as convective heat flux)
  • GLD sticker for all models (to measure convective heat flux only)
  • BLK - GLD sticker series can also be ordered pre-applied at the factory
  • With 5 or 10 m cable length
  • Separate cable in 2, 5, or 10 m lengths
  • Without wiring, without connection block
  • LI19 hand-held read-out unit/datalogger (NOTE: LI19 measures heat flux only) 


Heat Flux Sensors That Cover Most Heat Flux Measurement Applications

FHF05 series heat flux sensors are designed for general-purpose heat flux measurements. They are available in five dimensions, with larger sizes offering higher sensitivity and a larger area over which heat flux is averaged. These heat flux sensors are thin, flexible, and versatile, making them adaptable to various applications.

Heat Flux Sensors for All Applications

Image Credit: Hukseflux Thermal Sensors B.V.

These heat flux sesnors measure heat flux through the object in which it is incorporated or mounted, providing measurements in W/m². The sensor in FHF05 series, utilizes a thermopile to measure the temperature difference across its flexible body. Additionally, a type T thermocouple is integrated. Both the thermopile and thermocouple are passive sensors, meaning they operate without requiring an external power source.

Moreover, these heat flux sensors incorporate multiple small thermal spreaders that create a conductive layer covering the sensor. This design significantly reduces the measurement's dependence on thermal conductivity. Thanks to these integrated spreaders, FHF05 series' sensitivity remains consistent regardless of its environment.

The passive guard area surrounding the sensor decreases measurement errors caused by edge effects and is also utilized for installation.

Heat Flux Sensors with Unique Features and Benefits

  • Integrated type T thermocouple
  • Robustness, including connection block, for strain relief
  • IP protection class: IP67 (essential for outdoor applications)
  • Integrated thermal spreaders for low thermal conductivity dependence
  • Flexible (bending radius ≥7.5 x 10⁻³ m)
  • Low thermal resistance
  • Wide temperature range
  • Fast response time
  • Large guard area

Heat Flux Sensors for All Applications

Image Credit: Hukseflux Thermal Sensors B.V.

Easy to Use to Measure Heat Flux

FHF05 series is very easy to use. It can be directly connected to commonly used data logging systems. The heat flux in W/m² is calculated by dividing the FHF05 series output, a small voltage, by the sensitivity. The sensitivity is provided with FHF05 series on its certificate.

Heat Flux Sensors That are Robust and Stable

Equipped with a connection block, which may serve as a strain relief, and with potted protective covers on both sides so that moisture does not penetrate, FHF05 series has proven to be very robust and stable.

The calibration of the FHF05 series is traceable to international standards. The factory calibration technique adheres to ASTM C1130–21 recommendations.

Heat Flux Sensors for All Applications

Image Credit: Hukseflux Thermal Sensors B.V.

BLK and GLD Sticker Series

If you are looking for ways to obtain a detailed analysis of energy transport or heat flux, Hukseflux can help. 

We can elevate your measurements with FHF05 series. Opt for these heat flux sensors equipped with radiation-absorbing black (BLK) and radiation-reflecting gold (GLD) stickers.

With these additions, you can measure both convective and radiative flux using one set and solely convective flux with the other. By subtracting the two measurements, users can obtain the radiative flux.

Heat Flux Sensors for All Applications

Image Credit: Hukseflux Thermal Sensors B.V.

You can apply BLK (black) and GLD (gold) stickers to the sensor yourself. Stickers tailored to each sensor dimension are available. Alternatively, they can be pre-applied upon request. Refer to the BLK - GLD sticker series user manual and installation video for application instructions.

Heat Flux Sensors for All Applications

Image Credit: Hukseflux Thermal Sensors B.V.

Heat flux sensors | Latest technology to measure heat flux

Video Credit: Hukseflux Thermal Sensors B.V.

FluxTeq PHFS-01 and Omega HFS-5 Heat Flux Sensors Compared to Hukseflux FHF05 Series: Test Results

The sensor buyer might be of the opinion that for reliable heat flux measurement,

  • The sensitivity remains constant over time; stability
  • The sensitivity mentioned on the calibration certificate can be trusted; it is independent of the sensor’s surroundings

Close-up of an FluxTeq PHFS-01/Omega HFS-5 heat flux sensor. The thermopile is made using printing technology. Two different metal-filled electrically conducting inks are printed into through-holes.

Close-up of an FluxTeq PHFS-01/Omega HFS-5 heat flux sensor. The thermopile is made using printing technology. Two different metal-filled electrically conducting inks are printed into through-holes. Image Credit: Hukseflux Thermal Sensors B.V.

Testing at Hukseflux has shown that FluxTeq heat flux sensors (model PHFS-01) and Omega heat flux sensors (model HFS-5) are less stable compared to Hukseflux-manufactured sensors, and their sensitivity is influenced by the surrounding environment.

In situations requiring traceable measurements, users must consider these factors in their uncertainty assessment. Consequently, this results in a significantly higher measurement uncertainty than the 5% indicated on the PHFS-01 and HFS-5 calibration certificates.

You can read in detail about these test results on the product page of the FHF05 series on the website.

Application of These Heat Flux Sensors

Suggested Use

The FHF05 series heat flux sensors include sensors for general-purpose heat flux measurement, which are frequently used as part of a broader test- or measuring system. In contrast, the FHF05SC series is a self-calibrating variant of the basic model FHF05 series paired with an HTR02 series heater.

The FHF05SC series is suitable for long-term heat flux monitoring and where the greatest level of quality assurance is required. These self-calibrating sensors come in 50 × 50 and 85 × 85 sizes.

Other Equipment by this Supplier

Azthena logo powered by Azthena AI

Your AI Assistant finding answers from trusted AZoM content

Azthena logo with the word Azthena

Your AI Powered Scientific Assistant

Hi, I'm Azthena, you can trust me to find commercial scientific answers from

A few things you need to know before we start. Please read and accept to continue.

  • Use of “Azthena” is subject to the terms and conditions of use as set out by OpenAI.
  • Content provided on any AZoNetwork sites are subject to the site Terms & Conditions and Privacy Policy.
  • Large Language Models can make mistakes. Consider checking important information.

Great. Ask your question.

While we only use edited and approved content for Azthena answers, it may on occasions provide incorrect responses. Please confirm any data provided with the related suppliers or authors. We do not provide medical advice, if you search for medical information you must always consult a medical professional before acting on any information provided.

Your questions, but not your email details will be shared with OpenAI and retained for 30 days in accordance with their privacy principles.

Please do not ask questions that use sensitive or confidential information.

Read the full Terms & Conditions.