Wbgt Measurement - TESTO 400 Instruction Manual

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
- Ambient temperature T
- Humidity temperature T
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
Socket 2: Connection cable of ambient and
humidity temperature probe (T
Ensure that the specified instrument and cable temperatures are not exceeded.
You should work with extension cables, particularly in the case of high radiation
Switch on instrument: WBGT appears in the display
Location
40.0
26.4
Tg °C
WBGT
20.5
Tnw °C
36.6
22.3
WBGTS
Ta °C
Downloading using testo Comsoft software
Duct assignment is as follows:
Duct: K:1
Unit: °C
Assignment: T
g
g
a
(temperature of a naturally
nw
temperatures.
Calculate using the following formulae:
WBGT = 0.7 x T
WBGTS = 0.7 x T
°C
(with influence of solar radiation)
°C
K:2 K:3 K:4
°C °C °C
T T WBGT WBGTS
nw a
)
g
, T )
a nw
+ 0.3 x T
nw g
+ 0.2 x T + 0.1 x T
nw g
K:5
°C
44

WBGT measurement

Cu-CuNi NTC
(Type T)
T T
a g
1
T
g
a
NTC
T
nw
2
T , T
a nw