Thermal Coefficient; Wet-Bulb Globe Temperature - Ahlborn ALMEMO 710 Operating Instructions Manual

Converting to standard conditions
With all flow sensors it is possible to convert the measured values obtained un-
der the actual measuring conditions to standard conditions (i.e. temperature =
20 °C and atmospheric pressure = 1013 mbar). The actual measuring condi-
tions, i.e. temperature and atmospheric pressure, are determined using the
same device settings that may already have been set for temperature compen-
sation and pressure compensation.
By select the function `Standardized volume flow` and entering the temperature
and atmospheric pressure in the measurement the standard volume flow is
calculated accordingly.

To ensure that output data at the interface is converted in this way,
´#N´ must be programmed in the channel designation either already
in the velocity channel or in the volume flow channel. (see 13.2.1).

14.6 Thermal coefficient

To determine the thermal coefficient
are connected as required (see Manual 3.2) to channels M0.0 and M1.0 and
the heat flux plate to M2.0. Temperature difference T(M1)-T(M0) is acquired
on channel M1.1 as ´Diff´ and calculated on channel M2.1 as thermal coeffi-
cient.
For this measuring operation the following programming is required:
Quantity for M1.1:
Averaging mode for M1.1:
Averaging mode for M2.0:
Quantity for M2.1:
Default reference channels
Enter cycle in
Start measuring by pressing
Stop measuring by pressing

14.7 Wet-bulb globe temperature

The stress caused in heat-exposed workplaces can be evaluated in terms of
their wet-bulb globe temperature calculated according to the following formula :
WBGT=0.1DT + 0.7HTN + 0.2GT (see Manual 3.1.4)
To measure the dry temperature (DT) and the natural humid temperature (HT)
a psychrometer (FN A848-WB) with turn-off motor is connected at socket
M0.0. A Pt100 globe thermometer is connected at socket M1.0. The wet-bulb
globe temperature is calculated on channel M1.1 as quantity WBGT.
Volume flow measurement
/
q the two temperature sensors
(T1−T0)
Diff
CONT or CYCL
CONT or CYCL
q/dt
Mb1 = q = M2.0
Mb2 = Diff = M1.1
Output cycle
START
STOP
ALMEMO ® 710 73