Yokogawa Integral Oxygen Analyzer ZR202 - Manual (Page 98)

<7. Startup>
7-10
IM 11M12A01-02E
Enter
Primary value:
Oxygen

Secondary value:
mA-output1

Tertiary value:
mA-output2

Tag name:
Display item
F7.14.ai
Primary value:
Oxygen

Secondary value:
mA-output1

Tertiary value:
mA-output2

Tag name:
Enter
Oxygen
Item of output1 damping
Item of output2 damping
Display item
F7.15.ai
Figure 7.14 Display Item Display Figure 7.15 Display Item Selection
Table 7.2 Display Items
Item Primary value Secondary and
tertiary values
Display
Oxygen
concentration
○ ○
Oxygen concentration during measurement
Air ratio
○
Current computed air ratio
Moisture quantity
○
Moisture quantity (%H
2
O) in the exhaust gas
Output 1 item
○ ○ Oxygen concentration with the equipment set for oxygen
analyzer (See *1 below.)
Output 2 item
○ ○ Oxygen concentration with the equipment set for oxygen
analyzer (See *1 below.)
Current output 1
○
Current value output from analog output 1
Current output 2
○
Current value output from analog output
*1: If an analog output damping constant is set, the oxygen concentration display then includes these settings.
About the Air ratio:
“Air ratio” is defined as the ratio of (the amount of air theoretically required to completely burn all
the fuel) to (the amount of air actually supplied).
For this equipment, the air ratio will be obtained in a simplified way by measuring the oxygen
concentration in the exhaust gas. The air ratio may be expressed mathematically by:
m = { 1 / ( 21- Oxygen concentration ) }  21
If you use the air ratio data for estimating the combustion efficiency, etc., check that no air is
leaking in beforehand and that the measured value has not been affected by any interference
gas (CH
4
, CO, H
2
, etc.).
About moisture quantity:
The moisture quantity in the exhaust gas is calculated based on the parameters of the fuel
setting (refer to Section 8.6.3, Setting Fuels, later in this manual). The moisture content may be
expressed mathematically by:
Moisture quantity = {(water vapor content per fuel unit quantity) + (water content in air)}/ total
amount of exhaust gas
= { Gw + ( 1.61  Z  Ao  m )} / { X + ( Ao  m )}
where,
Gw = water vapor content in exhaust gas, m 3 /kg (m 3 /m 3 )
Z = Ambient absolute humidity, kg/kg
Ao = Ideal air amount, m 3 /kg (m 3 /m 3 )
m = Air ratio
X = Fuel coefficient
For details on each parameter, refer to Section 8.6.3, Setting Fuels.
8th Edition : Jan.13,2012-00