25-7 
 
5.  Open the relief valve to vent standard CO
2
 and make sure that there is an excess gas 
flow through the T-shape connector to air. 
6.  Check the realtime CO
2
 value is within 6.0±0.3% in the [Calibrate CO2] menu. 
 
 
25.6.3 Calibrating CO
2
For the CO
2 
module, a calibration is needed every year or when the measured values have a 
great deviation. For maintream CO
2
 module, no calibration is needed. Calibration for the CO
2
 
module can be performed only when the module enters the full accuracy mode. 
 
 WARNING 
z  Connect an exhaust tube to the gas outlet connector of the monitor to remove the 
calibration gases to a scavenging system. 
 
 
Tools required:   
  A steel gas cylinder with 6±0.05% CO
2
 and balance gas N
2
 
  T-shape connector 
  Tubing 
 
Follow this procedure to perform a calibration:   
1.  Make sure that the CO
2
 module has been warmed up or started up. 
2.  Check the airway for leakage and perform a leakage test as well to make sure the airway 
has no leakage. 
3. Select [Main Menu] [Maintenance >>] [User Maintenance >>] enter the 
required passwordė[Module Maintenance >>] [Maintain CO
2
 >>] [Calibrate 
CO
2
 >>]. 
4. In the [Calibrate CO
2
] menu, select [Zero]. 
5.  After the zero calibration is finished successfully, connect the equipment as follows: