Procedure for the determination of the average MRTDav
The average MRTD (MRTDav) is determined as follows:
1) Draw a graphic of spatial frequency (vertical axis) against temperature difference (horizontal axis) Using values obtained from the MRTD-graph, The resulting graph shows the “spatial resolution function" (SRF).
fig. 1 MRTD-curves.
fig. 2 SRF-curves.
4) Repeat step 2 and 3 for a number of values of temperature difference ΔT.
5) Draw a curve, using the average SRF-values found at step 3 and 4
6) Reverse the process of step 1. Draw the MRTD--curve with spatial frequency along the horizontal axis and temperature difference along the vertical axis. For the average MRTDav-curve use the calculated average SRFav-values.