Preparation for Installation  27 
 
Example of sample conditioning 
 
1 
Sampling point with primary shut-off valve 
2 
Multi-way ball valve 
3 
3/2-way ball valve
 1)
 
4 
Fine-control valve 
5 
Flowmeter with needle valve and alarm contact 
6 
2-way ball valve
 1)
 
7 
2-way ball valve
 1)
 
8 
Air filter
 1)
 
9 
Gas analyzer 
10 
Flowmeter without needle valve, with alarm contact 
11 
Purge gas cylinder with N
2
 1)
 
12 
Test gas cylinder with e.g. 2 ppm of O
2
 in N
2
 2)
 
13 
Test gas cylinder with 8 ppm O
2
 in N
2
 1)
 
14 
Pump
 1)
 
15 
Needle valve
 1)
 
1) Option 
2)  A hard-mounted test gas cylinder is normally adequate.  
The annual check of the reference point can also be carried out with 
a non-stationary air supply.