M&C TechGroup PMA 20 Operator's manual - Manual (Page 20)

20
Gas sampling and gas conditioning technology 9-3.5.1-ME

Connect the hose end of the instrument air or check gas bottle connection to the gas inlet
of the analyser.

Open the pressure reducer valve slowly, to avoid pressure peaks.

Adjust the flow rate to 50 Nl/hr at the flow meter.
N O T E !
Always calibrate at the flow rate that is adjusted for the measurement
too.

Wait approximately 20 – 30 sec. until the indication has stabilised.

If necessary adjust span accurately according to the check gas concentration with a screw
driver at the span potentiometer in the front panel. In case of air e.g. to 20,9 % O
2
.

Check output signals at 20,9% O
2
:

Shut off pressure reducer valve and bottle- resp. Instrument air valve resp. integrated
sample gas pump.

Disconnect hose connection at the analyser.
Determination of the output signal:
(S
e
– S
np
) V resp. mA x gas concentration Vol % O
2
upper range value Vol % O
2
Se = Final value, signal output
Snp = Zero, signal output

Shut off pressure reducer output valve and bottle valve. Druckreglerausgangsventil und
Flaschenventil schließen. Disconnect hose connection at the analyser.
The span calibration is finished.
N O T E !
If during the span calibration great variations have to be compensated
(>2% O
2
) at the potentiometers, a second zero and span calibration is
reasonable.
A T T E N T I O N After finishing the calibration turn measuring selection switch to the
desired measuring range.
The mA-output signal is dependant on the measuring range!
Output signal Measurement
range 100 % O
2
Measurement
range 30 % O
2
0-1 V 0,209 V 0,697 V
0-20 mA 4,18 mA 13,93 mA
4-20 mA 7,34 mA 15,15 mA
+ S
np