Teledyne T200U, Дополнение к руководству, Страница: 17 / 26

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4. PNEUMATICS
Figure 4-1 shows the internal pneumatics of the T200U in its standard
configuration, along with the optional Zero/Span valves. The sample flow
is 1000 cc/min.
Also, during Auto Zero mode, the sample gas is routed through a pre-
reactor before the mixture goes through the reaction cell. Since the
reaction rate constant between NO and ozone is several times faster than
the reaction rate constant between hydrocarbons and ozone, this
mechanism helps to eliminate the interference effects of hydrocarbons in
NOx measurements.
In addition, the T200U is equipped with a high performance pump,
capable of producing a reaction cell pressure of less than 5 Inch Hg
absolute.
SAMPLE
PRESSURE
SENSOR
VACUUM
PRESSURE
SENSOR
FLOW PRESSURE
SENSOR PCA
INSTRUMENT CHASSIS
PERMAPURE
DRYER
PREREACTOR
Orifice Dia.
0.004" PMT
GOLD
REACTION
CELL
PUMP
SAMPLE
GAS
INLET
NO/NO
X
VALVE
NO
2
Converter
O
3
Destruct
EXHAUST
GAS OUTLET
O
3
GENERATOR
O
3
Cleanser
PREREACTOR
VALVE
Orifice Dia.
0.004"
Orifice Dia.
0.014"
NC
COM NO
NC
COM NO
SPAN
ZERO
ZERO/SPAN
VALVE
SAMPLE/CAL
VALVE
OPTION, ZERO/SPAN
VALVES, P/N 042340100
NC
COM
NO
NC
NO COM
Orifice Dia.
0.007"
Figure 4-1. T200U Pneumatic Diagram with Zero/Span Option