Siemens ULTRAMAT 23, Manual, Page: 72 / 244

Connecting
5.2 Gas connections and internal gas path
ULTRAMAT 23
72
Manual, 3/2016, A5E37100388-003
Path for AUTOCAL/zero gas
The gases for the AUTOCAL calibration must be sucked in via a fine filter. The amount of the
measured gas component must be negligibly small in the AUTOCAL gas (zero gas). In
particular when carrying out an AUTOCAL for CO
2
ranges <1%, the air must be routed via a
CO
2
absorber (e.g. soda lime).
Path for chopper section purging
With CO
2
ranges < 0.1%, the chopper section is purged with clean nitrogen or CO
2
-free
synthetic air at an inlet pressure of 300 ... 350 kPa (43 ... 51 psi).
Path for pressure sensor
The internal atmospheric pressure sensor is routed via a hose to connection 6. It is therefore
possible to connect the pressure sensor (e.g. when using analyzer cabinets or houses) such
that it is guaranteed that only changes in atmospheric pressure are recorded.
5.2.2 Gas preparation
The sample gas must be sufficiently conditioned to prevent contamination of the parts
through which it flows. The ULTRAMAT 23 is usually preceded by the following elements:
● Gas sampling device with filter
● Sample gas cooler
● Analysis filter (approx. 1-2 μm)
● External gas suction pump (with sample gas lines >20 m/65 1/2 ft)
Note
In the analyzer version with the sample gas path as pipes, there is no safety filter and no
condensation trap in the internal gas path.
• Therefore correct gas preparation must always be ensured.
•
Depending on the composition of the sample gas, additional equipment may be
necessary such as e.g.
– A washbottle
– Additional filters
– Pressure reducer.