Hukseflux

Thermal Sensors

HFP03

Ultra sensitive heat flux plate / heat flux sensor
HFP03 is an ultra sensitive sensor for measurement of small heat fluxes in the soil as well as throughwalls and building envelopes. The total thermal resistance is kept small by using a ceramics-plastic
composite body. See also model HFP01: putting several HFP01 sensors electrically in series is analternative for using HFP03.

Introduction
HFP03 measures heat flux through the object inwhich it is incorporated or on which it ismounted, in W/m2. HFP03 is specifically suitable
for measurement of small flux levels, in the orderof less than 1 W/m2, for instance in geothermal
applications. The sensor in HFP03 is a thermopile.
This thermopile measures the temperature
difference across the ceramics-plastic composite
body of HFP03. A thermopile is a passive sensor;
it does not require power.
Using HFP03 is easy. It can be connected directly
to commonly used data logging systems. The
heat flux in W/m2 is calculated by dividing theHFP03 output, a small voltage, by the sensitivity.
The sensitivity is provided with HFP03 on its
calibration certificate.

Figure 1 HFP03 ultra sensitive heat flux plate

Calibration
HFP03 calibration is traceable to international
standards. The factory calibration method follows
the recommended practice of ASTM C1130.

Standards
HFP03 can be used for on-site measurement ofbuilding envelope thermal resistance per unit
area (R-value) and thermal transmittance (Uvalue) according to the standardised practices ofISO 9869, ASTM C1046 and ASTM 1155.

Uncertainty evaluation
The uncertainty of a measurement with HFP03 isa function of:•sensor properties•
calibration uncertainty•
measurement-related uncertainties, forexample uncertainty caused by thetemperature dependence of the sensitivity

Figure 2 opposite side of HFP03, which has a blue
coloured cover

The user should analyse his own experiment andmake his own uncertainty evaluation. Moreinformation can be found in the HFP03 manual.

Copyright by Hukseflux. Version 1606. We reserve the right to change specifications without prior notice
Page 1/2. For Hukseflux Thermal Sensors go to www.hukseflux.com or e-mail us: info@hukseflux.com

Hukseflux

Thermal Sensors
HFP03 specifications
Measurand
Sensing area
Sensor thermal resistanceSensor resistance range
Sensor thickness
Uncertainty of calibration
Measurement range
Sensitivity (nominal)
Rated operating temperature
range
Cable diameter
IP protection classStandard cable length
Optionsheat flux
64 x 10-4 m2
71 x 10-4 K/(W/m2)
10 to 32 Ω
5.4 x 10-3 m± 6 % (k= 2)-2000 to 2000 W/m2
500 x 10-6 V/(W/m2)-30 to +70 oC
4 x 10-3 m
IP67
5mlonger cable length(10, 15, 20, 30, 40 m)

Options•longer cable, in multiples of 5 m, cable
lengths above 20 m in multiples of 10 m

See also
•

13

•

•

putting multiple HFP01’s in series creates ahigh-sensitivity measurement at a lower costthan when using HFP03. It also has theadvantage of spatial averaging over a larger
area.
if measuring in soil, in case a high level ofquality assurance and accuracy of themeasurement is needed, consider use ofmodel HFP01SC.
view our complete range of heat flux sensors.

About Hukseflux
5.4
172

Figure 3 HFP03 heat flux plate: (1) 8 x sensing area,(2) passive guard of ceramics-plastic composite, (3)cable, standard length is 5 m. Total sensor thickness
including covers is 5.4 x 10-3 m. Dimensions in x 10-3 m.

Suggested use••

extremely small heat fluxes
geothermal heat flux

Hukseflux Thermal Sensors offers measurement
solutions for the most challenging applications.
We design and supply sensors as well as test &measuring systems, and offer related services
such as engineering and consultancy. With ourlaboratory facilities, we provide testing services
including material characterisation andcalibration. Our main area of expertise ismeasurement of heat transfer and thermal
quantities such as solar radiation, heat flux andthermal conductivity. Hukseflux is ISO 9001:2008
certified. Hukseflux sensors, systems andservices are offered worldwide via our office inDelft, the Netherlands and local distributors.

Interested in this product?
E-mail us at: info@hukseflux.com

Copyright by Hukseflux. Version 1606. We reserve the right to change specifications without prior notice
Page 2/2. For Hukseflux Thermal Sensors go to www.hukseflux.com or e-mail us: info@hukseflux.com