| Environmental Quality Branch
CODES,
CRITERIA
AND
MORE
Air
Audit Criteria for Continuous Air Quality Monitors:
CEMs and Ambient Air Quality
Updated: December 1999
Continuous
Gaseous Analyzers 1.
A graph of the observed (y-axis analyzer response) versus
the calculated (x-axis) gas concentrations is plotted.
2.
The slope intercept and correlation coefficient are
calculated.
3.
Monitor performance is evaluated using the following
regression criteria:
Regression
Curve: Linear
Slope |
Excellent |
< ± 5%
|
Between
analyzer response and audit concentration |
Satisfactory |
>
± 5% to ± 15% |
Between
analyzer response and audit concentration |
Unsatisfactory |
>
± 15% |
Between
analyzer response and audit concentration |
|
Intercept |
Satisfactory |
< ± 3% |
Of
the analyzer range |
Unsatisfactory |
>
± 3% |
Of
the analyzer range |
|
Correlation
Coefficient |
Satisfactory |
0.995
to 1.000 |
Linear
analyzer response to audit concentration |
Unsatisfactory |
< 0.995 |
Non-linear
analyzer response to audit concentration |
|
Time
to Reach Stability at Calibration Point |
Satisfactory |
<
20 minutes or |
Stable
|
|
Meets
manufacturer's specifications |
Stable |
Unsatisfactory |
20
minutes or |
Unstable |
|
Fails
to meet manufacturer's specifications |
Unstable |
A CEM or continuous ambient air quality analyzer will
FAIL an audit if:
- all
regression criteria are not met;
- the
error at any given calibration point is greater than
15%;
- the
deviation of reference and observed values at zero
point is greater than 3% of the analyzer range;
- analyzer
observations fail to stabilize within 20 minutes after
introduction of the calibration gas at any given calibration
point;
- the
analyzer is unavailable for auditing by the ministry
during a scheduled audit;
- the
analyzer is calibrated by the operator after notification
has been received of an impending audit. This condition does not apply to daily spans and does
not apply if calibrations are part of a routine maintenance
schedule which has been previously documented and
made available for verification by ministry audit
staff;
- the
operator does not have, or fails to keep current,
a logbook* of calibration and maintenance activities or the logbook is unavailable for review by the audit
staff at the time of an audit. A CONDITIONAL FAIL,
which will not result in increased audit frequency,
may be issued if the analyzer otherwise passes the
audit.
Continuous
Particulate Monitors: TEOM
A
TEOM continuous particulate monitor will FAIL an audit if:
- the
flow rate fails to meet the technical specifications
published by the manufacturer;
- a
leak check fails to meet the technical specifications
published by the manufacturer;
- the
KO calculation demonstrates an error greater than
3.0%;
- the
monitor is unavailable for evaluation by the ministry
during a scheduled audit;
- the
monitor is calibrated by the operator after notification
has been received on an impending audit. This condition does not apply if calibrations are
part of a routine maintenance schedule which has been
previously documented and made available for verification
by ministry audit staff;
- the
operator does not have, or fails to keep current,
a logbook* of calibration and maintenance activities or if the logbook is unavailable for
review by the audit staff at the time of an audit.
A CONDITIONAL FAIL may be issued if the monitor otherwise
passes the audit.
*Logbook:
All work performed on CEMs, ambient air quality monitors
and meteorological monitors must be recorded in a monitoring
logbook. The logbook is a journal that should be kept
at the monitoring station. It should not be confused
with Operator Logs (sometimes referred to as Monthly
Reports) which are servicing information forms that
are submitted routinely to Ministry data management
staff.
The
logbook must be kept current and must be available onsite
for review by Ministry auditors. It should be maintained
by the technicians responsible for the calibration,
maintenance and repair of the monitoring equipment and
must contain the following:
- Date
of service activity;
- All
data relevant to a calibration; calibration values
and settings (span pot, zero pot, etc.);
- Document
nature, date and time of any adjustments that are
made (span changes, zero changes, etc.) and reasons
for those adjustments;
- Description
of any repairs that are made (lamp replacement, quartz
tube replacement, etc. and reasons for the repair);
- Description
and date of equipment malfunction, modifications or
replacement;
- Documentation
of routine maintenance actions (perm tube replacement,
filter exchange, etc.)
For More Information:
Environmental Quality Branch
Ministry
of Environment
Government of British Columbia
PO
Box 9341
Stn Prov Govt
Victoria, British Columbia
Canada V8W 9M1
http://www.env.gov.bc.ca/air/
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