The device reports thermal bridges (sometimes with an audible warning or using a colour code).
In the example above, an ambient temperature of 19,9°C at a relative humidity of 70% results in a dew point temperature of 14.2°C. Here the surface temperature of the wall is 19,4°C, so there is no risk of mould.
The device does not detect the mould spores but indicates the conditions for their development using the dew point temperature that is compared to the wall surface temperature.
>>> There is a risk of mould when the air humidity is too high and/or the wall temperature is too low and below the dew point temperature calculated by the device.
The device may be equipped with additional functions like:
- measurement of the contact temperature (via a type K thermocouple probe – attention to surrounding electromagnetic disturbances)
- “Hot Point” or “Cold Point” function
- best possible level of resolution (up to 76 800 pixels (320 x 240) for a better accuracy of distance measurements)
- led lighting of the measured area
- photos and/or videos taking and saving (cable transfer, bluetooth, wifi).
For an optimal result, the measuring gun must be directed perpendicularly to the centre of the surface to be measured. Bright surfaces (or highly reflective) and transparent materials (glazing) must be excluded as reliable values cannot be obtained by this process.
Attention, the measurement of relative humidity may be distorted by the emanation of paints, varnishes or other chemical products.
It is advisable to aerate before taking the measure, to allow the ambient temperature to rise to a usual value and only then to take the measure.
It is also advisable to take several measures at different times and periods of the day to set the results according to different conditions.
The solutions to prevent mould development are:
- regular ventilation (or permanent or automated depending on air humidity),
- increase of ambient temperature by favouring radiant heating in order to increase the surface temperature of the wall,
- removal of thermal bridges and improvement of insulation (if possible). A good insulation mechanically pushes the internal condensation out towards the outside of the wall. It increases the surface temperature of the inner wall, therefore keeping it away from the dew point.