M&C 1803436, Инструкция по эксплуатации, Страница: 17 / 53

www.mc-techgroup.com PMA 50 EX | 1.01.04 17
13
GAS FLOW DIAGRAM
Figure 3 shows the gas flow diagram of the Oxygen Analyzer PMA50 EX .
1 : External fine filter
2 : External flow meter
3 : breathing and draining device
4 : Measuring cell
5 : Flow alarm sensor
6 : breathing and draining device
3
4
5 6
2
1
Figure 3 Gas flow diagram
The measuring cell
4 must absolutely be protected against dust particles. Therefore, the upstream external
gas conditioning system should be equipped with a fine filter 1 of at least 2 μm filter porosity (eg. type FP-
2T ).
The maximum gas flow of 60 Nl/h can adjusted by an externally mounted flow meter
2 with a needle valve.
The sample gas enters the measuring cell
4 via the inlet breathing and draining device 3 .
A flow sensor
5 in the outlet of the measuring cell is controlling the gas flow through the cell according to
the measuring principle of thermal conductivity. If the minimum gas flow is not reached, an alarm is auto-
matically triggered and is available as a status message at the collective status output. The status is also indi-
cated by a color change of LED
14 (see Figure 1) on the front panel of the analyzer (red/green).