BAM 1020-9800 Manual Rev W.docx
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unpredictably biased. The BAM 1020 cannot automatically detect a leak at the
tape/nozzle interface because the airflow sensor is located downstream of the filter
tape. Allowing a significant leak to persist may result in concentration data being
invalidated! Routine leak checks and nozzle cleaning prevent any significant leaks from
forming. Performing an as-found leak check before cleaning the nozzle or performing any
service is needed for validating data collected since the last successful leak and flow check.
Even if the leak check value is found to be within acceptable bounds, the nozzle and vane
should still be cleaned if any buildup or debris is noticed.
5.5
Leak Check Procedure
Perform the following steps to check for leaks in the BAM 1020 system:
1. Enter the TEST > TAPE menu. This will stop the operation cycle of the BAM 1020.
Press the FWD soft key to a
dvance the tape 1 “window” to a clean, unused spot.
2. (Optional) Some users perform an as-found flow check/audit before performing any
further service. If so, install your flow reference on the inlet, and check the 16.70 flow
point in the TEST > FLOW screen. Record the as-found flow rate, but do not calibrate
any of the flow parameters until the leak checks and nozzle cleaning are finished.
3. Remove the PM
10
head from the inlet tube and install a BX-305 or equivalent leak test
valve onto the inlet tube. If a PM
2.5
cyclone is used, install the leak check valve on top
of the cyclone, since the cyclone is a possible source of leaks and should be tested.
Turn the valve to the ON position.
4. Enter the TEST > PUMP menu and turn the pump on. Allow the flow rate to stabilize
and then press the LEAK button to turn on the leak test mode. This will prevent the
flow controller from rotating during the test.
5. Turn the valve on the inlet to the OFF position to prevent any air from entering the inlet
tube. The standard flow rate shown on the BAM display should stabilize at less than
1.0 L/min in about 20 seconds. Record the as-found results. If the leak flow value is
greater than 1.0 L/min, then there may be a leak in the flow system. If the leak value is
greater than 1.5 L/min, then there may be a significant leak.
6. If a leak is indicated, resolve it. First attempt the leak check again with the PM
2.5
cyclone removed (if used). Then clean the nozzle and vane as described below and
perform the check again. When the leak is resolved and the leak check value is less
then 1.0 L/min, record the as-left leak value.
7. Turn the leak test mode and the pump off.
8. Slowly open the leak test valve and then remove it. Go on to the nozzle and vane
cleaning and the flow tests as described below.
Interpreting Leak Test Results:
•
A properly functioning BAM 1020 with a clean nozzle and vane will often have a leak
value under the 1.0 L/min limit. It is typically about 0.5 L/min
. The exact “best case”
leak value for a particular unit varies depending on the type of pump used and the
local altitude.
