AIWTEC is usingARP5905 recommanded device to evaluated injected droplets Median Volumetric Diameter. This is Spraytech MALVERN instrument.
This value is necessary to characterized droplet distribution and requested in icing standard
MVD measurement have been validated on large temperature range. That permits to cover from -35°C to -5°C and also positive temperature up to +30°C. Temperature coefficient introduction is needed to obtain reliable MVD values.
Whatever the maximum speed of the subsonic IWT, due to very high acuisition frequency of the MALVERN instrument, there is no risk of degrading accuracy on the whole IWT speed range
MVD measurement in such condition pemit to follow set up evolution during test as alternate condition between CM (Continuous Maximum) and IM (Intermittent Maximum) condition for instance.