34
•
Using filtered (particle-free) pressurized air, blow the inside of the sensing
chamber taking great care in not marring or scratching any of the exposed
surfaces;
•
Reposition the two sensing chamber cover plates in the same location (front and
back) as they had been originally. Insert and tighten socket head screws firmly
making sure that the two plates are aligned perfectly with the top of the sensing
chamber;
•
Reposition large protective bumper over sensing chamber pushing down until
properly seated. Insert the two top screws holding down the bumper and tighten
gently (do not over-tighten);
•
Check optical background by zeroing the
p
DR-1000AN as indicated in Section
8.1. If the sensing chamber cleaning was performed correctly, the message
CALIBRATION: OK should be displayed at the end of the zeroing period.
12.2.2
Model pDR-1200
•
Remove the two screws (one in the front and one in the back) holding the front
and back gasketed covering plates of the sensing chamber, and set these plates
aside, such that they may be reattached in the same location as they were
previously.
•
Using filtered (particle-free) pressurized air, blow the inside of sensing chamber
taking great care in not marring or scratching any of the exposed surfaces.
•
Reposition the two sensing chamber cover plates in the same location (front and
back) as they had been originally. Insert and tighten socket head screws firmly
making sure that the two plates are aligned perfectly with the top of the sensing
chamber.
•
Check optical background by zeroing the pDR-1200 as indicated in Section 8.1.
If the sensing chamber cleaning was performed correctly, the message
CALIBRATION: OK should be displayed at the end of the zeroing period.
12.3
Cyclone Cleaning (Model pDR-1200 only)
The cyclone will require occasional cleaning. It is advisable to do so whenever the
sensing chamber of the
p
DR-1200 is cleaned (see above). To clean the cyclone,
remove it from its black attachment cup on the sensing chamber, and unscrew the
grit pot (narrower knurled end). Use clean pressurized air to blow out the grit pot and
through all openings of cyclone body. Reattach grit pot to cyclone body and insert
cyclone body into attachment cup making sure it is fully inserted.
13.0 CALIBRATION
13.1 Factory
Calibration
Each
personal
DataRAM is factory calibrated against a set of reference monitors that,
in turn, are periodically calibrated against a gravimetric standard traceable to the
National Institute of Standards and Testing (NIST).
