Download Report 2 - CSA Group

7.5
Basic Problem and Cause/Solution Table
The following table contains information on some of the more common BAM-1020 problems
which may be encountered, and some steps to identify and remedy the problems. Met One
welcomes customer suggestions for new items to include in this section of future manual
revisions. If the solution cannot be found in the following table, then contact one of our expert
service technicians for help in resolving your problem.
Problem:
Cause/Solution:
The BAM won’t start a measurement cycle.
• The unit is programmed not to start a sample cycle until the beginning of an hour.
Make sure the clock is set correctly.
• The unit will wait until the beginning of a new hour before it starts, even if the
operation mode is set to ON.
• Don’t expect the pump to turn on until the clean tape count is finished, about 8
minutes after the start of the hour.
• The unit cannot start if the pinch rollers are latched UP! The unit cannot lower them.
• Make sure the filter tape is installed correctly.
• The unit will never start a cycle if the display is left in a TEST or SETUP menu! The
main screen or OPERATE menu must be displayed.
• The unit will usually display an error if it cannot start a new sample cycle.
Problem:
Cause/Solution:
The analog output voltage and/or digital concentration reading are full-scale.
• The unit will force the analog and digital concentration values to full-scale (usually
0.985mg) to indicate that an error has prevented the collection of a valid hourly data
point, or that the hourly cycle was interrupted. Download the digital error log to
identify the cause. The current hourly record after power-up will also be full-scale.
Problem:
Cause/Solution:
The BAM hourly concentration is reading negative values.
• It is possible for the unit to occasionally read negative numbers if the actual ambient
particulate concentration is below the detection limit of the BAM-1020, such as
below 3 micrograms. This is because the BAM has a noise band of several
micrograms. This should not happen often.
• If the unit is reading negative numbers hour after hour, it may be punching holes in
the filter tape. These holes can be very small. This is almost always caused by
debris on the nozzle or vane. Clean the parts.
• The BKGD zero correction offset value may have been incorrectly entered, or may
need to be audited. Met One supplies the BX-302 zero filter kit for auditing the zero
average and noise floor of the unit. Set the BKGD value to 0.000 during the test.
• Look for sources of electrical noise, such as bad grounding. Any source of noise will
show up in the zero filter test.
• Verify that the inlet tube is grounded to the chassis of the BAM-1020.
Problem:
Cause/Solution:
The airflow rate is too low and won’t adjust up to 16.7 L/min.
• The gray plastic pump mufflers on the Medo pumps may clog up after several
months. Replace it or drill a hole in the end of it for a temporary fix. The brass
mufflers on Gast pumps can often be cleaned.
• Some users replace the pump muffler with a 30 inch length of air tubing. This will not
clog and reduces the pump noise as well as the mufflers do.
• The vacuum pump may need to be rebuilt after about 2 years. Medo pumps slowly
loose flow capacity as the pump wears out. Eventually, the flow capacity drops
below 16.7 lpm when it needs to be rebuilt.
• Checking the 18.4 L/min point during the regular 3-point flow audits verifies the
pump capacity.
• Check the inlet and PM heads for obstructions.
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BAM-1020-9800 REV K