ARCHIVED REPORTS_REMOVAL ACTION COMPLETION REPORT

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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 pDR-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 Basketed 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 pDR-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 personalDataRAM 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). The primary factory reference method consists of generating a dust aerosol by means of a fluidized bed generator, and injecting continuously the dust into a mixing chamber from which samples are extracted concurrently by two reference filter collectors and by two master real-time monitors (MIE DataRAMs) that are used for the routine calibration of every personalDataRAM. 29