BA 4510
NOTICE
To minimise the measuring error when measuring minimal oxygen concentrations, en-
sure the following measurement and equipment requirements are met:
a) Choose a location for extracting the sample gas to rule out any layers forming at the
extraction site.
b) The transport path for the sample gas to the measuring cell must be as short as pos-
sible to prevent a shift in the chemical balance along the way as best possible.
c) All gas supply and discharge lines must be absolutely tight.
d) Measuring oxygen concentrations < 1000 ppm requires stainless steel lines.
e) If the sample gas contains reducing components (e.g. alcohols), the concentration of
free oxygen cannot be determined, as chemical reactions occur at the electrode. In
these cases it is advisable to pass the sample gas through an activated carbon filter
before the gas inlet.
1.4.3 General Design
1.4.3.1 General Overview
This device is available in a portable, compact laboratory design. The general structure of the device is shown in figure 1.
Pressure regulator
(needle valve, optional
Gas inlet
Gas outlet
Flow meter
Measuring cell
Diaphragm pumps
Analysis electronics with display
Data exchange
Fig. 1: General layout, components
The sample gas is pushed into the measuring cell at minimal overpressure or, on the version with pump, suctioned through the
measuring cell. A needle valve and/or a pressure regulator can be installed before the gas inlet to control the flow rate. On the
version with pump the flow rate is kept at a constant by regulating the pump output.
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Bühler Technologies GmbH
BE550013 ◦ 09/2018
