Page 6-2
Airnet II Particle Sensor Operations Manual
Chapter 6
Troubleshooting
Airflow Rate Errors
As a result of the performance check procedure (see
), the flowrate at the
sensor’s inlet should be the following:
•
0.1 CFM for models 301, 501, and 501A 0.085 - 0.115 CFM (± 5 %)
•
1.0 CFM for models 510, 510s, and 510XR/510s XR 0.85 -1.15 CFM (± 5 %)
A flowrate error greater than 15 % (±5%) indicates that maintenance is required.
Low flow could be due to an obstructed orifice, leaks or insufficient vacuum.
A minimum of 15 inches of Hg ( > 410 mBar below atmospheric pressure) vacuum is
required at the Airnet II particle sensor’s critical orifice for the 510/510XR, and 510s/
510s XR units. Greater than 11 inches Hg (> 375 mBar below atmospheric pressure) is
required for the 301 and 501/501A units to provide the sample flowrate. If the flowrate
is still low after determining that there is sufficient vacuum, perform the following
procedure.
Isolating and Repairing Leaks
To isolate and repair leaks:
1.
Remove the top and bottom halves of the instrument.
2.
Run samples.
3.
While a sample is running, use a bulb syringe to blow a small amount of smoke
around the possible leak paths and watch for an increase in the number of counts.
The following locations are possible leak paths:
• Where the inlet jet meets the body of the sample block
• Around the laser diode
• Around the photodiode
• Around the laser window
• Around the beam dump
• Around the mirror plug
4.
If a leak is suspected around the inlet jet, remove the jet and O-ring, clean lubricate
and/or replace parts.
5.
Reassemble the unit.
6.
If a leak is suspected around the laser diode or photodiode, contact Particle
Measuring Systems for assistance.
