45
44
The NET (Normal Effective Temperature) climate index is determined using the 3 function probe
in accordance with DIN 33403. NET is used, for example, in the basic principles of the
Professional Association for High-Temperature Work (G30), to assess the maximum time which
can be spent working in extreme conditions (e.g. steel industry, foundries).
The following ambient variables are included in the calculation:
- Air temperature
- Air moisture
- Air flow
Connect the following to carry out the measurement:
Socket 1: 3 function probe (0635.1540)
Socket 2:
Do not connect probe!
Switch on instrument.
Allocate “NET” to one of the function buttons.
Press “NET” to start measurement.
NET is shown in the display:
Generally, the following data applies to NET measurement:
Ambient temperature:
15-50°C
NET range:
5-37°C
Downloading using
testo Comsoft
software
Duct assignment is as follows:
Duct:
K:1
K:2
K:3
K:4
Unit:
%
°C
m/s
°C
Assignment:Air
Air
Air
NET
moisture temp.
flow
NET measurement
The WBGT (Wet Bulb Globe Temperature) climate index is determined using the WBGT probe in
accordance with DIN 33403 and ISO 7243. The WBGT index is used to determine the maximum
permissible exposure time at high-temperature workplaces (e.g. steel industry, foundries, glass
industry or blast furnaces).
3 different temperatures have to be measured to calculate
WBGT:
- Radiation temperature T
g
- Ambient temperature T
a
- Humidity temperature T
nw
(temperature of a naturally
ventilated psychrometer)
Note:
Ensure that the water container
to measure humidity temperature
is sufficiently filled.
To carry out the measurement, connect the following:
Socket 1: Connection cable of globe thermometer (T
nw
)
Socket 2: Connection cable of ambient and
humidity temperature probe (T
a
, T
nw
)
Switch on instrument: WBGT appears in the display
Calculate using the following formulae:
WBGT = 0.7 x T
nw
+ 0.3 x T
g
WBGTS = 0.7 x T
nw
+ 0.2 x T
g
+ 0.1 x T
a
(with influence of solar radiation)
Downloading using
testo Comsoft
software
Duct assignment is as follows:
Duct:
K:1
K:2
K:3
K:4
K:5
Unit:
°C
°C
°C
°C
°C
Assignment: T
g
T
nw
T
a
WBGT WBGTS
WBGT measurement
T
a
T
g
T
nw
1
2
T
g
T
a
, T
nw
Location
40.0
Tg
°C
20.5
Tnw
°C
22.3
Ta
°C
Ensure that the specified instrument and cable temperatures are not
exceeded. You should work with extension cables, particularly in the case of
high radiation temperatures.
26.4
WBGT
°C
36.6
WBGTS
°C
i
Function buttons
Location
60.1
%
38.1
°C
0.2
m/s
32.8
NET
°C
NET
Cu-CuNi
NTC
NTC
(Type T)
