The entire setup was covered with aluminum foil to protect
the operator and to reflect the UV-C light emitted by the lamps. The
fluences measured with a radiometer at midway height in the tunnel
treatment zone, were 10, 5.2, 3.9 and 3.8 mW/cm2 at 1, 5, 10 and
15 cm from the lamps' surface to the center of the tunnel treatment
zone. This setup allowed us to study the effectiveness of UV-C light for
powder decontamination: the flow's effect was measured by varying
the shaker's vibration intensity, and total power consumption was tested
by modifying the number of lamps switched on, and the effect of the
distance travelled by the flour dust,was assessed by locating small platforms
of 3 cm of width, at 43, 93 and 143 cm, measured from the top of
the tunnel