Bio-Science CI-900, Operation Manual, Page: 40 / 94

CI-900 Instruction Manual 8/10/2015
1554 NE 3
rd
Ave, Camas, WA 98607, USA Phone: (360) 833-8835
sales@ cid-inc .com www.cid-inc.com
35
Enter the temperature on the display of the CI-900 as the “calibrated T” when the gain is adjusted.
Press
Save to save the new internal
gain calibration value.
Injection Parameters
With additional sensors added to the CI-900, additional internal volume is added and the amount of
volume becomes specific to each instrument and the amount of tubing used. In order to determine
the calibration volume for GC emulation mode using either CO
2
or O
2
sensors, the following formula
is used. The results are saved on your ethylene analyzer and in the Production Test Check Sheet in
this manual.

X
i
: Injected gas concentration (%)

X
o
: Initial concentration (%)

X
f
: Final concentration (%)

V
i
: Injected gas volume (mL)

V: Volume of gas stream in instrument (mL)
In GC emulation mode, start a measurement and setup the injection port (chambers off, closed loop
off). Record stabilized value of target gas. This value is X
o
. Next, prepare injection gas (such as 4%
CO
2
or 50% O
2
), record V
i
and X
i
, then inject gas. Record stabilized value “X
f
” of target gas. Calculate
V using the formula above. This should be repeated several times, and the average should be taken.
The average calibrated volume (V) has been determined and entered in the Setup>Calibration>
press enter>CO
2
or O
2
>Injection Parameters menu by a technician at the factory.
Offset Autocorrection
Offset autocorrection allows the unit to adjust the baseline, or zero, for the ethylene sensors, which
may drift from the zero set at the time of calibration. The offset autocorrection procedure typically
takes about 25-30 minutes and takes place during “Sensor Stability”, the first screen when
measurement mode is initiated. The default interval between offset autocorrections is 24 hours for
continuous use, or during the next start-up for units that are not running continuously. If the unit is
exposed to concentrations greater than 200 ppm during the measurement period, the offset
autocorrection will be initiated the next time the user enters “Sensor Stability”, even if less than 24
hours have passed.
The offset autocorrection relies on there being KMnO
4
in Chamber Out.
X = measured concentration
Original gain standard gas concentration
Offset Autocorrection
Adjust enable
Yes
interval (hour) 024
requesting Yes
V= ((X
i
-X
o
)*V
i
)
(X
f
-X
o
)