9. Measuring using Measuring-Menus
9.6 Assistant-Menus for Special Meas. Operations
Special measuring operations, i.e. thermal coefficient or wet bulb globe tempe-
rature, require a series of sensors in a particular arrangement and function
channels programmed for calculating the required variables. To ensure that
these two special measuring operations can be performed quickly and easily
there is a special assistant menu for each.
9.6.1 Thermal Coefficient
To determine the thermal coefficient
q
/
T1
−
T0
the two temperature sensors
are connected as required (see manual, sec-
tion 3.2) to channels M0 and M1, and the
heat flow plate to M2. The temperature diffe-
rence T(M1)-T(M0) is obtained automatically
on channel M5.
For this measuring operation the following
programming steps are needed :
Averaging mode on M5 :
CONT
or
CYCL
Averaging mode on M2:
CONT
or
CYCL
Range on M12:
q/dt
Enter the cycle by means of:
Cycle timer
Start measuring by means of:
<START>
Stop measuring by means of:
<STOP>
9.6.2 Wet Bulb Globe Temperature
The stress caused in heat-exposed work-
places can be evaluated in terms of their wet
bulb globe temperature calculated according
to the following formula:
WBGT=0.1TT + 0.7HTN + 0.2GT (s.man.
3.1.4)
To measure the dry temperature (DT) and
the natural humid temperature (HT) a psy-
chrometer (FN A848-WB) with turn-off motor
is connected to socket M0 and a Pt100 globe
thermometer is connected to socket M1. The
output on channel 11 is programmed to
WBGT; (for this device the factor 0.2 must
not be programmed !).
40 ALMEMO 2690-8
Assistant-Menu
Thermal Coefficient:
Assistant-Menu Wet Bulb
Globe Temperature:
Inner temp. T0:
Channel: 00
00: 21.67°C NiCr
Outer temp. T1 : Channel: 01
01: 11.42°C NiCr
Difference dt: Channel: 05
05: 10.25°C Diff
Averaging mode: CONT
Heat flow q
Channel: 02
02: 103.6 ¤¥
Averaging mode: CONT
±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±
T
hermal coeff. Channel: 12
12: 193. ¤mK q/dt
1 Range: q/dt
Cycle-timer:
00:30:00 Sn
START MANU PRINT ESC
WET-BULB-GLOBE-TEMP.
¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯
Dry temperature: Channel: 00
00: 21.67°C Ntc
Humid temp:
Channel: 10
10: 11.42°C HT
Globe temp:
Channel: 01
01: 19.42°C P204
±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±
Wetbulbglobetemp: Channel: 11
11: 17.43 °C
1 Range:
WBGT
START MANU PRINT ESC
