11. Function menus
11.2 Averaging
The
average value
for a measured value is needed for various applications
e.g. smoothing a widely fluctuating measured value (wind, pressure etc.).
Average flow velocity in a ventilation channel
Hourly or daily average values for weather data (temperature, wind, etc.)
Also for consumption values (electric current, water, gas, etc.)
The average value M for a measured variable is obtained
by totaling a whole series of measured values Mi and then
dividing by the number of measured values N.
If, in function selection, averaging is selected a new selection menu will appear
listing the various averaging modes.
These include measured value smoothing for
the selected channel with a sliding averaging
window, averaging over individual measuring
operations selected by place or time, averaging
over time, over cycles, or over specified mea-
suring points. For flow sensors a special menu
for array measuring as per VDE is provided.
To select the averaging menu press key(s) :
and
or
PROG
To clear averaging for the selected channel press : <CLR>
11.2.1 Smoothing meas values by means of a sliding average
The first method for averaging applies exclu-
sively to the measured value of the selected
channel; it is used to smooth measured values
of an unstable or strongly fluctuating nature,
e.g. especially turbulent flows, by means of a
sliding average over a specified time frame.
The
level of smoothing
can be set in the
Smoothing
function; here you specify the
number of measured values to be averaged (possible range 0 to 99). The
smoothed measured value can thus also be used in all subsequent evaluation
functions in combination with averaging over individual measured values (see
11.2.2) or for networked measuring (see 11.2.7).
Measured value smoothing over e.g. 15 values :
Smoothing: 15
Continuous measuring point scanning should be disabled
32 ALMEMO
®
2590
M
=
∑
i
m
i
/
N
13: 25.45
m/s
L840 flow
Smoothing
15
Mªª M FCT
Averaging :
Sliding average, smoothing :
over meas operations ©
over time
over cycle
over measuring points
Array measuring
Mªª F © CLR
M
=
∑
i
M
i
/
N
m1
m15
time window
Summary of Contents for ALMEMO 2590-2
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