3-20 
3.4.8 Mainstream CO
2
 Tests 
NOTE 
z  Select [Main Menu]→[Maintenance >>]→ [User Maintenance >>]→enter the 
required password→[Maintain CO
2
], make sure that the setting of [Barometric 
Pressure] is correct before performing mainstream CO
2 
tests. 
 
Tools required: 
  A steel gas cylinder with 6±0.05% CO
2
 
  A steel gas cylinder with compressed air or N
2
 (with standard concentration) 
  Two 3-way valves (power supply controlled) 
  Flowmeter 
  Power supply 
  Tube 
 
Follow this procedure to perform the test: 
1. Wait until CO
2
 warmup is finished and then select [Start Zero Cal.]from [CO
2
 Setup] 
menu to start a zero calibration. If the zero calibration fails, the prompt message [CO
2
 
Zero Failed] is displayed. Otherwise, the baseline of waveform recovers to zero. 
2 Set [Apnea Delay] to 10 s in the [Adjust CO
2
 Limits] menu. 
3 Blow to the CO
2
 sensor to generate a CO
2 
waveform and then place the sensor in the air. 
Check if the alarm message [CO
2
 Apnea] is displayed on the screen. 
4  Connect the test system as follows