Lighthouse ApexP3, Operating Manual, Page: 94 / 130

Lighthouse ApexPortable Operating Manual
6-2 248083440-1 Rev 5
8. Run the test.
9. If more than one count is reported during the four five-minute
samples, allow the instrument to sample for 30 minutes to purge it
then repeat the test. If the second run fails, contact Lighthouse
support.
10. After the instrument has met the requirements of the Zero Count
test, return the instrument to its normal location and operating
status.
Fault Isolation
If the instrument does not pass the Purge Count test, perform the
following procedure:
1. Check the data over the last 6 five-minute sample times.
2. If sporadic counts are occurring over all channels, the unit may
still have particles inside it. Allow the unit to sample overnight
with the purge filter attached before retesting it. If the counts are
still high after the overnight purge, call Lighthouse Technical
Support for assistance.
3. If the data shows consistent counts in the smallest channel only,
the instrument may have electrical problems and may need to be
returned to Lighthouse. Call a Lighthouse Service Representative
for assistance.