CIRAS-3 Operation Manual V. 1.09
67
Startup and Warm up
Press and release the ON/OFF button, it should illuminate blue. It takes approximately 30 seconds for
the first Welcome display to appear on the console screen.
Press either
Continue (F1)
or
Settings (F2)
– at this point this is not important since the system is not
quite ready to operate. “Warm up (temp) C…” appears in the status bar at the bottom of the screen,
where initial (temp) should be close to ambient temperature °C. Note that the initial temperature depends
on the ambient temperature where CIRAS-3 is located. Warm up time to the required 55 °C IRGA
temperature can vary based on ambient temperature. The warm up period can be only several minutes
in a mild or warm environment (in the laboratory) and longer if it has been stored in a colder environment.
Automatic Zero and Differential Balance (Diff Bal) cycles will run during warm up, in each case counting
downward from a fixed number of cycles. Zero counts down 30 cycles while Diff Bal counts down 25
cycles. Each cycle takes less than one minute.
Once the IRGA achieves its target temperature of 55 °C, it will then perform both a Zero and Diff Bal cycle
at time 0, 6, 12, 23, 39 and 59 minutes. After this, it will perform a Zero only once every 31 minutes
followed by a Diff Bal. A Diff Bal cycle will also take place when there is a large change in CO
2
(100 µmol mol
-1
) or H
2
O (5 mb) concentration.
F1
F3
F2
F4
F6
F5
F7
F8