PERFORMANCE
SPECIFICATION 4A - SPECIFICATIONS AND TEST PROCEDURES FOR CARBON MONOXIDE
CONTINUOUS EMISSION MONITORING SYSTEMS IN STATIONARY SOURCES
2.0 Summary of
Performance Specification.
8.0 Sample Collection,
Preservation, Storage, and Transport.
8.1 Relative Accuracy
Test Procedure.
8.3 Response Time Test
Procedure.
8.3.1 Introduce zero
gas into the analyzer.
9.0 Quality Control.
[Reserved]
10.0 Calibration and
Standardization. [Reserved]
12.0 Calculations and
Data Analysis.
14.0 Pollution
Prevention. [Reserved]
15.0 Waste Management.
[Reserved]
18.0 Tables, Diagrams,
Flowcharts, and Validation Data.
1.0 Scope and Application.
1.1 Analytes.
1.2 Applicability.
1.2.1 This
specification is for evaluating the acceptability of carbon monoxide (CO)
continuous emission monitoring systems (CEMS) at the time of installation or
soon after and whenever specified in an applicable subpart of the regulations.
This specification was developed primarily for CEMS that comply with low
emission standards (less than 200 ppmv).
1.2.2 This
specification is not designed to evaluate the installed CEMS performance over
an extended period of time nor does it identify specific calibration techniques
and other auxiliary procedures to assess CEMS performance. The source owner or
operator is responsible to calibrate, maintain, and operate the CEMS. The
Administrator may require, under Section 114 of the Act, the source owner or
operator to conduct CEMS performance evaluations at other times besides the
initial test to evaluate CEMS performance. See 40 CFR Part 60, Section
60.13(c).
1.2.3 The
definitions, performance specification, test procedures, calculations and data
analysis procedures for determining calibration drifts (CD) and relative
accuracy (RA), of Performance
Specification 2 (PS 2), Sections 3, 8.0, and 12, respectively, apply to
this specification.
2.0 Summary of Performance Specification.
The CD and RA tests
are conducted to determine conformance of the CEMS to the specification.
3.0 Definitions.
Same as in Section
3.0 of PS 2.
4.0 Interferences. [Reserved]
5.0 Safety.
This performance
specification may involve hazardous materials, operations, and equipment. This
performance specification may not address all of the safety problems associated
with its use. It is the responsibility of the user to establish appropriate
safety and health practices and determine the applicable regulatory limitations
prior to performing this performance specification. The CEMS users manual
should be consulted for specific precautions to be taken with regard to the
analytical procedures.
6.0 Equipment and Supplies.
Same as Section 6.0
of PS 2 with the following additions.
6.1 Data Recorder Scale.
6.1.1 This
specification is the same as Section 6.1 of PS 2. The CEMS shall be capable of measuring
emission levels under normal conditions and under periods of short duration
peaks of high concentrations. This dual-range capability may be met using two
separate analyzers (one for each range) or by using dual-range units which have
the capability of measuring both levels with a single unit. In the latter case,
when the reading goes above the full-scale measurement value of the lower
range, the higher-range operation shall be started automatically. The CEMS
recorder range must include zero and a high-level value. Under applications of
consistent low emissions, a single-range analyzer is allowed provided normal
and spike emissions can be quantified. In this case, set an appropriate
high-level value to include all emissions.
6.1.2 For the
low-range scale of dual-range units, the high-level value shall be between 1.5
times the pollutant concentration corresponding to the emission standard level
and the span value. For the high-range scale, the high-level value shall be set
at 2000 ppm, as a minimum, and the range shall include the level of the span
value. There shall be no concentration gap between the low and high- range
scales.
7.0 Reagents and Standards.
Same as Section 7.0
of PS 2.
8.0 Sample Collection, Preservation, Storage, and Transport.
8.1 Relative Accuracy Test Procedure.
Sampling Strategy for
reference method (RM) Tests, Number of RM Tests, and Correlation of RM and CEMS
Data are the same as PS 2, Sections 8.4.3, 8.4.4, and 8.4.5, respectively.
8.2 Reference Methods.
Unless otherwise specified
in an applicable subpart of the regulation, Methods 10,
10A, 10B, or other approved alternative is the RM for this PS. When evaluating
non-dispersive infrared CEMS using Method 10 as the RM, the alternative interference
trap specified in Section 16.0 of Method 10 shall be used.
8.3 Response Time Test Procedure.
The response time
test applies to all types of CEMS, but will generally have significance only
for extractive systems.
8.3.1 Introduce zero gas into the analyzer.
When the system
output has stabilized (no change greater than 1 percent of full scale for 30
sec), introduce an upscale calibration gas and wait for a stable value. Record
the time (upscale response time) required to reach 95 percent of the final
stable value. Next, reintroduce the zero gas and wait for a stable reading
before recording the response time (downscale response time). Repeat the entire
procedure three times and determine the mean upscale and downscale response
times. The slower or longer of the two means is the system response time.
8.4 Interference Check.
The CEMS must be
shown to be free from the effects of any interferences.
9.0 Quality Control. [Reserved]
10.0 Calibration and Standardization. [Reserved]
11.0 Analytical Procedure.
Sample collection and
analysis are concurrent for this performance specification (see Section 8.0).
Refer to the RM for specific analytical procedures.
12.0 Calculations and Data Analysis.
Same as Section 12.0
of PS 2.
13.0 Method Performance.
13.1 Calibration Drift.
The CEMS calibration
must not drift or deviate from the reference value of the calibration gas, gas
cell, or optical filter by more than 5 percent of the established span value
for 6 out of 7 test days.
13.2 Relative Accuracy.
The RA of the CEMS
must be no greater than 10 percent when the average RM value is used to
calculate RA, 5 percent when the applicable emission standard is used to
calculate RA, or within 5 ppmv when the RA is calculated as the absolute
average difference between the RM and CEMS plus the 2.5 percent confidence
coefficient.
13.3 Response Time.
The CEMS response
time shall not exceed 1.5 min to achieve 95 percent of the final stable value.
14.0 Pollution Prevention. [Reserved]
15.0 Waste Management. [Reserved]
16.0 Alternative Procedures.
16.1 Under conditions
where the average CO emissions are less than 10 percent of the standard, and
this is verified by Method 10, a cylinder gas audit may be performed in place
of the RA test to determine compliance with these limits. In this case, the
cylinder gas shall contain CO in 12 percent carbon dioxide as an interference
check. If this option is exercised, Method 10 must be used to verify that
emission levels are less than 10 percent of the standard.
17.0 References.
Same as Section 17 of
PS 4.
18.0 Tables, Diagrams, Flowcharts, and Validation Data.
Same as Section 18.0
of PS 2.