HD31
- 27 -
V1.6
NET index:
T
H
v
H
T
NI
•
⎟
⎠
⎞
⎜
⎝
⎛ −
•
−
•
+
+
•
−
−
−
=
100
1
29
.
0
4
.
1
76
.
1
1
0014
.
0
68
.
0
37
37
75
.
0
With T = temperature in °C
H = relative humidity in %
v = air speed in m/s
NET index provides the so called “apparent temperature”: with optimum weather conditions, the
index value is close to the environmental T temperature. As weather conditions deteriorate, hu-
midity and air speed influence become more and more evident and the index provides a tem-
perature value that reflects human typical sensations, deviating even significantly from the am-
bient temperature value:
•
in hot climate, the NET index rises as temperature and/or humidity level increases, but it
decreases with increasing wind force;
•
in cold climate, the NET index decreases with temperature and with increasing humidity
and wind level.
Summary of Contents for HD31
Page 6: ...HD31 6 V1 6 2 DESCRIPTION Fig 2 1 instrument description...
Page 149: ...HD31 149 V1 6 NOTES...
Page 150: ...HD31 150 V1 6 NOTES...
Page 151: ......
