3-21 
 
In the figure above, 
 
1  A steel gas cylinder with 6±0.05% CO
2
 
2 Flowmeter 
3  3-way valve (power supply controlled) 
4  Open to air 
5  Power supply   (controlling two 3-way valves) 
6  Compressed air or N
2
 with standard concentration 
7 Mainstream CO
2
 sensor 
8 Patient monitor  
9  Tube (preventing back flow) 
 
5  Adjust the power supply and turn on/off 3-way valves to ensure that that only one 
cylinder is connected to the Mainstream CO
2
 sensor via the 3-way valves at one time 
and the flowmeter reading is stable and within 2 and 5L/min. 
6  Switch between the two cylinders to connect Mainstream CO
2
 sensor at an intervals of 6   
to 10s and check if the displayed CO
2
 value is within 6.0±0.3%. 
 
 
3.4.9 Sidestream and Microstream CO
2
 Module Tests 
See section 3.2.3 Sidestream and Microstream CO
2
 Module Tests. 
 
 
3.4.10 AG Tests 
See section 3.2.4 AG Tests.