Met One E-BAM, Руководство по эксплуатации

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E-BAM-9805 Manual Rev B.docx Page 54
5.13 Basic Problem and Cause/Solution Table
The following table contains information on some of the more common problems that may be
encountered, and some steps to identify and remedy the problems. Met One Instruments, Inc.
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 the Met One Instruments, Inc.
service technicians for help in resolving the problem. See section 1.2.
Problem:
The mass monitor won’t start a measurement cycle.
Cause/Solution:
•
The mass monitor will not start a measurement cycle if it detects a hardware failure,
such as low beta count signal, pressure sensor failure, or pump failure.
•
The mass monitor will not start a cycle if either the zero-membrane plate or
the shipping shim is inserted.
•
The mass monitor will not start a cycle if the 597A sensor is not connected.
•
The mass monitor will not start a cycle if the filter tape is not installed correctly.
•
The mass monitor will usually display an error message on the display if it cannot
start a cycle.
•
If the mass monitor is left in a SETUP or FIELD CALIBRATION screen, it should still
try to start a cycle after several minutes of inactivity, unless a failure is detected.
Problem:
The mass monitor records frequent “Pressure Drop Excessive” errors.
Cause/Solution:
•
This usually indicates that the filter tape is automatically advancing in response to
being clogged due to heavy particulate loading.
•
If frequent pressure-drop errors are encountered, try setting the TAPE ADVANCE
setting to a shorter interval. See section
3.6.5.
When hourly PM readings are high,
more frequent tape advance intervals may be required.
Problem: The concentration indicates negative values.
Cause/Solution:
•
It is possible for the mass monitor to occasionally record negative hourly values if
the actual particulate concentration is extremely low. This is because the mass
monitor has an hourly random noise band of several micrograms.
•
The real-time averages of the mass monitor (especially the 1- and 5-minute
averages) are considerably noisier than the hourly measurements. These noise
spikes may indicate negative concentrations unless the true concentrations are high.
•
The noise performance of the mass monitor may be audited. Met One Instruments
supplies the BX-302 zero filter kit for auditing the zero readings of the mass monitor.