Shellab SCO10A-2 - Manual (Page 11)

11
E. The micro processor CO
2
control system interprets the information from the CO
2
sensor, displays the
CO
2
concentration directly on the digital display, reads the CO
2
set point and controls the percentage
of CO
2
in the incubator chamber.
F. The CO
2
sensors operate under the principal that a certain frequency of infrared light is absorbed by
CO
2
. The more CO
2
is present the more light is absorbed. Advantages to this system are that it is
only sensitive to CO
2
, so its accuracy is consistent no matter what the conditions, temperature and
RH) are in the incubator.
G. CO
2
sensors are factory calibrated and under normal circumstances need no calibration in the field. It
is recommended that the accuracy of the CO
2
control system be monitored. By measuring the actual
CO
2
concentration on a weekly basis using a Fyrite or other measuring device. This should be done
when the chamber has not been disturbed for an extended period of time i.e. after the weekend, or
first thing on Monday morning.