LumaSense Technologies INNOVA 1314i - Manual (Page 95)

Chapter 8
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BE6030-13 1314i Photoacoustic Gas Monitor LumaSense Technologies A/S
Page 95 of 199
Where: N = measurement cycles performed during the
monitoring period (T) between the cursors.
c
n
= gas concentrations (where n = 1 to N)
The Standard Deviation (σ) – this is the standard deviation of a
particular gas’s measurements from the mean value (µ) of this
gas. Standard deviation can be expressed mathematically as
follows:
The Standard Deviation =
( )
1
1
2
-
-
=
å
=
=
N
Cn
N n
n
m
s
Where: µ = the mean value
C
n
= individual gas concentrations
N = total number of measurements
8.2.2 Symbols used in Displayed Measurement Data
If an asterisk (*) appears on the display alongside any gas
concentration, it indicates that something happened during the
measurement. You can find out what the asterisk indicates by
pressing the INFO button. The following display appears for a short
period of time:
GAS X: COMMON MARK: PEOW GAS MARK: BFA
TIME: hh:mm
The symbols which can appear after the text COMMON MARK and
GAS MARK are listed below with a short explanation of what they
mean:
Common Marks:
“P” (1) The Monitor stopped measuring due to a power
failure but has automatically re-started the
monitoring task again after regaining power;
(2) The Monitor has been “reset” either because of
a detected fault or because RESET was pressed.
“O” This symbol indicates that an operational error was
detected during this measurement. The accuracy of
such a measurement cannot always be guaranteed.