Divesoft He/O2 Analyzer, Руководство пользователя

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He/O
2
Analyzer
| 19 |
Special accessories
using the partial pressures method and its precision depends on the blender’s experience and
estimation.
If we know the current gas pressure, tank temperature, gas composition and ambient
temperature, we can predict the extent of this decrease on the base of a calculation according
to the state equation.
The analyzer can perform this calculation automatically if the temperature sensor is
attached to the pressure sensor. The complete assembly for simultaneous measuring of the
gas composition and pressure including the tank temperature is shown in the illustration. The
temperature sensor is attached to the tank with a flexible Velcro strap.
After connecting the temperature sensor, the measured pressure is shown in the basic
display format.
In the scale of 0–400 bars, similarly as in the case of separate pressure measuring but
supplemented with other data which show the anticipated pressure after the tank cools, for
example bars, similarly as in the case of separate pressure measuring but supplemented with
other data which show the anticipated pressure after the tank cools, for example
Oxygen: 20.1 %
Helium: 30.5 %
Temperature: 25.5 °C
0 202.6 bar @ 32.1 °C
\ 190.0 bar @ 25.5 °C
The fourth line shows the actual pressure and temperature of the tank; the fifth line shows
the pressure after cooling to the stated temperature. The state equation is used for calculating
the measured gas composition.
The temperature of the tank after cooling can be selected in Menu/Preferences/Ref.temp.
source . When selecting the Ambient variant, the current ambient temperature (or, more preci-
sely, the temperature of the analyzer’s aluminum body) is used; with the Defined variant, the
temperature set in the following menu item (Ref. temperature) is used.
With the
MODE
key, it is possible to select the third display format which shows the
absolute and relative pressure, both as current and anticipated after cooling, for exampled
bar Actual @ 25.5 °C
Abs: 202.6 190.0
Rel: 52.6 49.3
Tank temp.: 32.1 °C
The measured tank temperature is used also in some of the He/O
2
analyzer’s other modes (display
of the results of the gas-blending calculation, emergency disconnection of the filling station).