8-16 Model 3772/3771 Condensation Particle Counter
Nozzle or orifice
pressure out of range;
aerosol flow rate is out
of range
Orifice pressure is <10 or >90
kPa; Nozzle pressure is <1 or >6
kPa.
Apply sufficient external vacuum.
Contact a TSI service technician.
Butanol liquid is present in the
instrument optics causing a
variety of problems including
erratic or very low concentration
readings and/or changes in
transducer pressure
measurements.
Although the 3772 and 3771 CPCs have been designed
to resist flooding, it can occur if the instrument is shipped
without properly drying or removing a wet wick. Flooding
can also occur if the inlet is blocked or the instrument is
tipped during operation.
Once the instrument cover is removed, evidence of
flooding is seen by examining tubing for the presence of
liquid. Start by looking at tubing connected to the pressure
transducers. Carefully remove and dry out wet tubing then
replace. Note: Don’t dry the tubing in place to avoid
damaging other parts in the CPC.
If flooding has occurred, it will be necessary to dry the
optics block.* Begin by draining the butanol and removing
the wick as described earlier. Replace the saturator base
without replacing the wick. Turn the instrument on and
make sure the external vacuum is on and the fill bottle is
disconnected. Allow the instrument to operate for at least
20 hours. Refer to “Correcting Flooded Optics” for detailed
instructions.
Detector in the laser indicates low
laser power.
Contact a TSI service technician.
Liquid level sensor in the reservoir
does not detect the presence of
butanol.
Verify that no liquid is present in the reservoir by taking off
the cover of the CPC and looking through the reservoir
window. If it is difficult to identify the liquid level, using a
flash light and tipping the CPC a couple degrees are
helpful. If no liquid level line is seen, check carefully to
confirm that it is not overfilled, indicating a problem in the
butanol level detection circuitry.
Add butanol to the fill bottle and connect the bottle at the
quick connect fitting.
Make sure the Auto Fill Enable is selected ON in the User
Settings menu (Figure 4-6).
Watch the reservoir to confirm that it fills then stops. If
filling does not occur, the fill filter may need to be
replaced. Refer to “Changing the Filters” presented
earlier.
*Flooding can contaminate the lens surfaces in the optics block reducing signal strength and instrument sensitivity. Lens
cleaning is performed at the factory if flooding occurs. A noticeable change in instrument performance characteristics (e.g.,
lowered detected concentration) can indicate the need to return the instrument to TSI for maintenance.
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