FHF05 Series Heat Flux Sensors

Specifications

Options
• with 5 or 10 meter cable length
• separate 2, 5 or 10 meter cable length
• no cabling, no connection block
• LI19 handheld data logger/reader unit
NOTE: LI19 measures heat flux only
• BLK adhesive for all models (for measuring radiative and convective heat flux)
• GLD adhesive for all models (for measuring convective heat flux only)
• BLK-GLD adhesive series can also be ordered factory pre-applied
Downloads
FHF05 Series Heat Flux Sensors Brochure (PDF, 896.5 KB)
FHF05 Series Heat Flux Sensors User Manual (PDF, 1.81 MB)
Hioki LR8450 Data Logger and FHF05 Series Heat Flux Sensors in Battery EV Thermal Management (PDF, 1.81 MB) 1.88 MB)

Description

Heat flux sensors that cover most heat flux measurement applications
Sensors of the FHF05 series are suitable for general-purpose heat flux measurement. The range consists of five different dimensions. Larger dimensions mean a higher sensitivity and a larger area over which the heat flux is averaged. They are thin, flexible and versatile. FHF05 measures heat flux through the object in which it is incorporated or on which it is mounted, in W/m². The sensor in FHF05 is a thermopile. This thermopile measures the temperature difference across FHF05’s flexible body. A type T thermocouple is integrated as well. The thermopile and thermocouple are passive sensors; they do not require power.

Multiple small thermal spreaders, which form a conductive layer covering the sensor, help reduce the thermal conductivity dependence of the measurement. With its incorporated spreaders, the sensitivity of FHF05 is independent of its environment. Many competing sensors do not have thermal spreaders. The passive guard area around the sensor reduces measurement errors due to edge effects and is also used for mounting.
Heat flux sensor, thin, flexible, versatile

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

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

Robust and stable heat flux sensors
Equipped with a connection block, which can serve as a strain relief, and with encapsulated protective covers on both sides to prevent moisture from penetrating, the FHF05 has proven to be very robust and stable.

The calibration of the FHF05 is traceable to international standards. The factory calibration method follows the recommended practice of ASTM C1130 - 21.
Heat flux sensor, absorbs radiation and reflects radiation

BLK and GLD sticker series
Would you like to study energy transport / heat flux in detail? Hukseflux helps you take your measurement to the next level: order the FHF05 with black stickers absorbing radiation and gold stickers reflecting radiation. You can then measure convective + radiative flux with one, and only convective flux with the other. Subtract the 2 measurements and you get the radiative flux. The BLK - GLD stickers can be applied by the user to the sensor. There are stickers for each sensor dimension. Optionally, they can be ordered pre-applied. Please refer to the BLK – GLD decal series owner’s manual and installation video for instructions.

Comparison of FluxTeq PHFS-01 and Omega HFS-5 thermal flow sensors with Hukseflux FHF05 series: test results
For accurate thermal flow measurement, the sensor buyer can reasonably assume that
• the sensitivity does not change over time; stability
• the sensitivity specified in the calibration certificate can be relied upon; that it is not dependent on the sensor environment

Tests performed at Hukseflux reveal that FluxTeq thermal flow sensors model PHFS-01 and Omega thermal flow sensors model HFS-5 are less stable than those manufactured by Hukseflux, and that their sensitivity is dependent on the environment. In applications requiring traceable measurements, users must take both factors into account in their assessment of uncertainty. This leads to a measurement uncertainty much higher than the 5% stated on the PHFS-01 and HFS-5 calibration certificate.

Suitable data loggers and amplifiers to work with Hukseflux heat flux sensors
Hukseflux offers a wide range of sensors for heat flux and temperature measurement. The thermopile heat flux sensor and thermocouple temperature sensor are both passive sensors; they do not require power.
Such sensors can be connected directly to data loggers and amplifiers. The heat flux in W/m² is calculated by dividing the heat flux sensor’s output, a small voltage, by its sensitivity. The sensitivity is provided with the sensor on its certificate and can be programmed into the data logger.

Optimize system design/reduce costs

The following text will help you select the right electronics for your application. Selecting the right combination of electronics and sensor helps reduce overall system costs.

Step 1
Visit the Hukseflux YouTube channel.

Step 2
Specify your measurement.

Step 3
Estimate the output range of the heat flux sensor.

Step 4
Specify your electronics and sensors.

Step 5
Ask Hukseflux for our feedback/suggestions.

Suggested use

Heat + temperature flux sensors and loggers are used to analyze the causes of temperature change. They are also used to validate mathematical CFD simulations.

Read the full article here:
Heat Flow Data Logger Selection Guide (PDF)
Heat movements can be visualized:
An application example

How to visualize heat movements in battery electric vehicles (BEV) to get feedback on battery performance and battery degradation rate? Hioki has investigated this topic. Read more about this research where they used their data loggers combined with Hukseflux heat flow sensors.