10. Installation of the HFM1
10.1 Location of the measurement area
The HFM1 should be installed such to ensure a result which is representative of the
element being measured, ideally where one-dimensional heat flow perpendicular to the
exterior surfaces occurs.
Infrared thermography can be used to assist determine the characteristics of the
building component when the internal configuration of the component is unknown.
Sources of error, such as thermal bridges, internal wall abnormalities and cracks should
be avoided.
The outer surface of the element should be protected from direct solar radiation;
artificial screens can be used for this purpose.
The more heat flux, the better; strongly cooled or strongly heated rooms are ideal
measurement locations. However, sensors shall not be under the direct influence of a
heating or cooling element, or under the draught of a fan.
Situations in which the heat flux is constantly changing direction are not ideal.
10.2 Mounting of the HFP01 Heat flux sensors
HFP01 sensors can be installed temporarily on the surface of a wall, or alternatively
integrated permanently into the wall.
The HFP01 should be mounted in direct thermal contact with the surface of the
element over the whole area of the sensor.
10.2.1 Temporary Installation
On smooth, flat surfaces, the HFP01 can be mounted using a guard ring made of
material which has similar thermal properties to the sensor. A layer of masking tape, or
some other thin material, will both match the HFT absorptance with that of most
nonmetallic finishes and provide a smooth transition for air flow.
In locations exposed to direct solar radiation or high air flow a layer of material over the
entire exposed surface of the HFT that matches the HFP surface absorptance to that of
the surrounding surface and creates a smooth transition for air flow.
On rough surfaces air gars between the HFP01 sensor face and element
should be filled.
Air gaps greater than 0.5 mm (0.02 in.) can cause errors from 2 to 10 % through
convection. Apply a heat conductive material, such as gel toothpaste or petroleum jelly
between the sensor face and element prior to mounting with adhesive guard ring.
10.2.2 Permanent Installation
Sensors built into the construction provide more reliable results than sensors mounted on
an exterior surface, as they are usually protected from radiant heat sources and
convection, which may affect the sensor differently than the surrounding building
material.
Enabling better research outcomes in soil, plant & environmental monitoring.
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