Parquet floor
In addition to data analysis usually performed for impulse-thermography, pulse-phase-thermography (PPT) is based on the frequency analysis of the transient curves recorded at the surface structure during cooling. The experimental set-up as well as the execution of the test is similar. Amplitude and phase images offer a selective, frequency-dependent visualisation of the internal structure of the device being tested. The differences between both image types are the following: amplitude images show the internal structure of a specimen up to a maximum available depth depending on the frequency (low pass filter behaviour). Phase images display the internal structure within a certain depth range depending on the frequency (band pass filter behaviour). As most of the available energy is concentrated in the low frequencies, amplitude images are less noisy as phase images. Phase images are less sensitive to inhomogeneous heating at the surface or to different optical properties at the surface (emissivities), e. g. due to surface contamination or surface roughness.
Thermogram
Phase image
Dr. rer. nat.