He/O
2
Analyzer
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Set-up
9. Set-up
9.1 Preferences
It is possible to change select properties of the analyzer in the basic mode (measuring of He/O
2
)
in
Menu/Preferences
. Individual parameters have the following significance:
Brightness
of the display in the scale of 1 to 127. The selection of low brightness (1) preserves
the battery; the highest brightness (127) is suitable for use in strongly lit places. For temporarily
increasing the display’s brightness, simply hold down the pressed .key.
When activating the
Heighten brightness
option, the brightness is automatically increased
to maximum if the analyzer is powered with an external power-supply adapter.
The option
O
2
cell used
is activated as standard. When deactivating, the O
2
value is ignored
and replaced with the value shown in the following
O
2
substitute
parameter. This option allows
emergency use of the analyzer with a worn-out oxygen sensor for measuring the concentration
of helium. In such a case, the correct setting of the oxygen concentration in the analyzed mix
increases the precision of measuring the concentration of helium (on the order of tenths of
a percent).
Averaging
activates the calculation of the moving average from the set number of values of
the He concentration. The number of averaged values is set with the
Values to avg.
parameter.
When activating averaging, the He concentration is displayed in square brackets (e.g. [25.7])
if the required number of values for calculating the average is not available.
Send data to USB
activates the sending of measured values to the USB interface.
Partial pressure O
2
is the maximum allowed partial pressure of oxygen used for calculating
MOD.
The
Ref. temp. source
option determines whether ambient temperature (
Ambient
) or defined
temperature (
Defined
) entered in the following
Ref. temperature
parameter is used for calculating
the estimated pressure in the tank (by using plug-in thermometer only).
9.2 Measurement units
Other settings are available in
Menu/Measurement units
. Here the analyzer can be switched to
metric mode (
Metric units
), imperial-units mode (
U.S. units
) or the display of individual units
can be selected separately for individual values (temperature, depth, pressure, volume, mass).
The unit settings do not affect the calculations (with the exception of final rounding), as the
analyzer works in SI units internally.
Notice:
Meters and feet are indicated as units of depth,
though in reality this concerns hydrostatic pressure (pressure at the indicated depth in seawater).
