3) optional functions, 5) standard requirements for sample gas, 4) performance – Yokogawa IR200 User Manual
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IM 11G02M01-01E
(3) Optional functions
O
2
correction:
Conversion of measured CO , SO
2
and
NO gas concentrations into values at
reference O
2
concentration.
Correction formula: C = –––––––– x C
s
C : Sample gas concentration after O
2
correction
C
s
: Measured concentration of sample
gas
O
s
: Measured O
2
concentration
O
n
: Standard O
2
concentration (value
changeable by setting)
*The upper limit value of the fractional
part in this calculation is 4.
The result of calculation is indicated and
output in an analog output signal.
Average value after O
2
correction
and O
2
average value calculation:
The result of O
2
correction or instanta-
neous O
2
value can be output as an av-
erage value in the determined period of
time.
Used for averaging is the moving aver-
age method in which sampling is carried
out at intervals of 30 seconds.
(Output is updated every 30 seconds. It
is the average value in the determined
period of time just before the latest up-
dating.)
Averaging time is settable within 1 to 59
minutes (in increments of 1 minute) or 1
to 4 hours (in increments of 1 hour).
Average value reset:
The above-mentioned output of average
value is started from the initial state by
applying a non-voltage rectangular wave
to the average value resetting input ter-
minals (opened after short-circuiting for
1.5 seconds or longer).
Output is reset by short-circuiting and
restarted by opening.
CO concentration peak count alarm:
(added only for CO
ϩ
O
2
measurement)
Alarm output turns on according to the
preset concentration and count.
Whenever the instantaneous value of CO
exceeds the preset concentration value,
count increments. If the count exceeds
the preset value in one hour, the alarm
contacts close.
Communication function:
RS-232C (9 pins D-sub)
Half-duplex bit serial
Start-stop synchronization
Modbus
TM
protocol
Contents :
Read/Write parameters
Read measurement concentration and
instrument status.
Remark : When connecting via RS-485 interface,
an RS-232C,/RS-485 converter should
be used.
(5) Standard Requirements for Sample Gas
Flow rate : 1
±
0.5 L / min
Temperature : 0 to 50˚C
Pressure : 10 kPa or less (Gas outlet side should be open
to the atmospheric air.)
Dust
: 100
µ
g/Nm
3
in particle size of 0.3
µ
m or less
Mist
: Unallowable
Moisture : Below a level where saturation occurs at room
temperature (condensation unallowable).
Below a level to cause saturation at 2˚C for
CO measurement with 0 to 200 ppm range
and SO
2
measurement.
Corrosive component: HCl, H
2
S, HF: 1 ppm or less
Standard gas for calibration:
Zero gas ; Dry N
2
Span gas ; Each sample gas having concen-
tration 90 to 100% of its measur-
ing range (recommended).
Gas beyond concentration 100%
FS is unusable.
In case a zirconia O
2
analyzer is installed
externally and calibration is carried out on the
same calibration gas line:
Zero gas ; Dry air or atmospheric air
(provided without CO
2
sensor)
Span gas ; For other than O
2
measurement,
each sample gas having concen-
tration 90 to 100% of its measur-
ing range.
For O
2
measurement, O
2
gas of 1
to 2 vol%
It is understood that a large quantity of
hydrogen, helium, or argon in sample gas
affects the calibration model of an infrared
gas analyzer (pressure broadening). When
measuring such sample gas, use a gas
which has similar composition to the
sample gas as a span gas.
21-O
n
21-O
s
(4) Performance
Repeatability
:
±
0.5% of full scale
Linearity
:
±
1% of full scale
Zero drift
:
±
2% of full scale/week
Span drift
:
±
2% of full scale/week
Response time (for 90% FS response):
1 or 2 component measurement;
Within 15 seconds including replacement
time of sample gas
More than 2 component measurement;
Within 30 seconds including replacement
time of sample gas
Interference from other gases:
Interference
component
CO
2
analyzer
SO
2
analyzer
CH
4
analyzer
CO
analyzer
CO 1000 ppm
CO
2
15%
H
2
O saturation
at 20
Њ
C
H
2
O saturation
at 2
Њ
C
Ϫ
Ϫ
Ϫ
Ϲ
2% FS
Ϫ
Ϫ
Ϫ
Ϫ
Ϲ
1%FS
Ϲ
1%FS
Ϲ
1%FS
for 500 ppm
analyzer,
Ϲ
2.5%FS
Ϲ
2.5%FS
for 200 ppm
analyzer
Ϲ
1%FS
Ϲ
1%FS
for 200 ppm
analyzer,
Ϲ
2.5%FS
Ϲ
1%FS
Ϲ
1%FS
Ϲ
1%FS
Ϲ
1%FS
CH
4
1000 ppm
Ϫ
Ϲ
1%FS
Ϲ
1%FS
Ϲ
50ppm
Ϫ
T02.EPS
Ϲ
50ppm
Ϲ
2%FS
with inter-
ference
compen-
sation
ء
Ϲ
60ppm
Ϲ
2%FS
with inter-
ference
compen-
sation
ء
NO
analyzer
Ϲ
1%FS
Ϲ
1%FS
Ϫ
Ϫ
Built-in
paramagnetic
O
2
analyzer
Ϫ
ء
The H
2
O interference of NO and SO
2
analyzer can be reduced by the
interference compensation.