Data Acquisition and Handling
System (DAHS) Approval Process
Richard Basso
PADEP, CEM Section
DAHS Revision 8 Approval Process



Amended Phase I (Monitoring
Plan)
Phase II (Performance Testing)
Phase III (Final Approval)
Purpose of DAHS Approval

Determine that the system will meet new
reporting format and code hours correctly.




Electronic data reports (EDRs) pass format check.
Emissions calculated correctly by the DAHS based
on analyzer readings and other calculation
factors.
Different operational circumstances reported
correctly.
Provides an opportunity to correct problems
discovered during the review.
Amended Phase I




Basic client information
Description of the DAHS
Installation schedule
DAHS calculation support
Basic Client Information

Source and process description


Will DAHS serve entire site or will there
be different DAHSs for different sources?
Continuous emission monitoring
system (CEMS) description



Type of CEMS (NOx, SO2, opacity,
temperature, etc.)
Units- lbs./hr, ppm, %, degrees, etc.
Fuel factor or coal sampling
Description of DAHS



Make, model, and software
version
Manufacturer’s literature
Consultant contact information
Installation Schedule

Proposed date DAHS will be installed.
(or actual date if completed)



During a source or plant wide outage.
In parallel with old DAHS. (both
collecting data)
Switch over from old DAHS to new DAHS
during normal operating hours, with
potential for data loss.
DAHS Calculation Support


Show how DAHS uses analyzer
readings to derive minute and hourly
values for each type of CEMS at the
facility.
Example spreadsheets or formulas,
including fuel factors, data
substitution, coal sampling and
analysis, and opacity path length
ratio correction (where applicable).
Phase II

Conduct the DAHS accuracy test:



9 hourly averages from the DAHS are
compared to 9 hours of manually or
separately calculated averages.
Test should be conducted for every
CEMSs at the facility.
Opacity systems also include a
separate comparison using 60 oneminute averages.
Phase III






Results of DAHS accuracy test
Schedule of DAHS upgrade
Example quarterly EDR files
Minute data for example hours
Example hours using data
substitution, if applicable
Excess files, if applicable
DAHS Accuracy Test

Submit results of DAHS accuracy
test.




Include both DAHS results and
separately calculated results.
Show table comparing differences with
error calculated.
Include additional 60 minute
comparison for opacity systems.
Electronic mail is preferred for
review of information.
DAHS Upgrade Schedule



Date and hour old DAHS stopped
collecting valid data.
Date and hour new DAHS started
valid data collection.
Explain operational circumstance.



Parallel data collection
Process outage
Note any hours of operational data that
may have been lost during the transition.
Phase III Example EDR Files

E-mail EDR files to the Department to
conduct a format check.




Only one file is needed for each type of
CEMS.
Example data may be used if real data is
not yet available.
Include excess and incident files for
Opacity and Temperature CEMS.
Show correct uses of Process Codes,
Monitoring Codes, and the new Method
of Determination Codes.
Phase III
Operating Circumstances Review

Send example hourly value and
supporting minute data or quadrant
data to support the following
circumstances:






Full hour of operation
Invalid hour of operation
Process down hour
Maintenance/quality assurance hour
Data substituted hour if applicable
Excess or incident reports if applicable to
support hourly data for opacity and
temperature CEMSs
Questions?