Yokogawa IR400 - Manual (Page 88)

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IM 11G02N01-01E
7.3.4 Moisture interference compensation adjustment method
Proceed to an adjustment if excessively (beyond
±
2%
FS) affected by moisture inteference.
After the end of optical balance adjustment, be sure to
carry out moisture inteference compensation adjust-
ment.
(1) After warm-up, select the low range, allow dry gas
(N
2
, air) to flow at 0.5 L/min and carry out zero
calibration.
If the following operation is maladjusted, the measurement may adversely be affected. If you are
not trained for adjustment, do not carry out this operation but contact the distributor or our service-
man.
Caution
N
2
or Air
Flow meter
Electrical
Cooling Unit
Water
Bubbler
Drain
Optical zero adjustment knob
Optical
system 1
Optical system 2
(3) Carry out the adjustment in the procedure in (4) and subsequent.
•
Adjust on the primary side of the optical system so that the values for a to d in 1-1 and
1-2 become as close to 0 as possible within
±
100 range.
•
Adjust on the secondary side of the optical system so that the values for e to h in 2-1 and
2-2 become as close to 0 as possible
within
±
100 range.
(9) After the optical balance adjustment, mount the top cover of the analyzer unit, then carry out
a moisture interference compensation adjustment, and perform zero and span calibrations.
* Before moving the dimmer plate, loosen the detector set bolts (just enough to make
the plate movable for snug adjustment).
(4) Operate the optical zero adjustment
knob to change the value displayed at
a (or e ).
(5) Move the dimmer plate sideview to
change the value displayed at b (or
f ).
(6) Move the dimmer plate sidewise to
change the value displayed at c (or
g ).
(7) Move the dimmer plate sidewise to
change the value displayed at d (or
h ).
(8) Repeat the procedures in (4) to (7) to
make all the displayed values come
close to 0 as possible within
±
100
range.
* Adjust the dimmer plate which is
the nearest to the zero adjustment
knob first, and sequentially.
Dimmer plate
Detector set bolt