TSI Instruments 9302, Owner'S Manual

Model 9302 Single-Jet Atomizer 

3 

To generate these particles, fill the Atomizer’s reservoir with the selected 
oil. The diameter of the droplets depends on the setting of the pressure 
regulator. For a setting of 25 pounds per square inch (172 kPa), the 
number mean diameter of the particles will be approximately 0.8 
micrometer. 

A d j u s t i n g   t h e   D i l u t i o n   A i r  

A design change has been made to the Model 9302 Atomizer. Previously, 
the entire airflow through the Atomizer passed through an orifice nozzle 
and generated particles. Thus, the full pressure drop was across the 
nozzle. A rough-adjustment screw has now been added to allow some of 
the pressure to bleed off as dilution air. (This is useful if the seeding 
concentration is too high.) Now, a portion of the pressure drop is across the 
nozzle and the rest of the pressure drop is across an orifice that supplies 
dilution air to the flow and decreases the concentration of particles out of 
the larger exit nozzle. 
 
The rough adjustment screw is factory-set to provide no dilution air. To 
change this setting, follow these steps: 

1.  Remove the plastic reservoir bowl from the bottom of the Atomizer. 

2.  Located along the outside diameter of the black aluminum cylinder 

(attached to the plastic cap) is a no. 10-32 setscrew. Turn it 
counterclockwise to open the orifice for dilution. Since slight rotation 
increases the dilution air substantially, withdraw the setscrew slowly. 
Several adjustments may be necessary before you achieve the correct 
particle density. 

Again, this adjustment is useful only if you want to decrease the 
particle concentration at the exit of the nozzle. This feature may be 
useful if you are looking at signals from the flow produced by the 
Atomizer. 

3.  To shut off the dilution air flow, turn the setscrew clockwise and tighten 

firmly. 

M a i n t e n a n c e   a n d   T r o u b l e s h o o t i n g  

Generally, the Atomizer requires little maintenance. However, should a 
piece of dirt become trapped in the parts of the jet-nozzle assembly, 
compressed air may bubble through the assembly’s long plastic tube. To 
correct this minor problem, simply dismantle the assembly and carefully 
clean each part.