Quality assurance of automated measurement systems

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Quality assurance of automated measurement systems
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Contents of this presentation

• EN14181 approach
• General
• Quality Assurance Level 1 (QAL 1)
• Quality Assurance Level 2 (QAL 2)
• Quality Assurance Level 3 (QAL 3)
• Annual Surveillance Test (AST)

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EN 14181 approach general (1)

• Incited by (European) environmental legislation
• Quality assurance of Automated Measurement
  Systems (AMS) without specification of
  measurement principle
• Netherlands Continuous and Predictive emission
  monitoring systems (CEMS and PEMS)
• Required uncertainty specified in
  legislation/permit
• Expressed as 95 confidence interval
• Confidence interval expressed as of emission
  limit value

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EN 14181 approach general (2)

• four Quality Assurance Levels (QAL)
• QAL1-3
• Annual Surveillance Test (AST)

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EN 14181 approach QAL1

• Once only during selection of measurement
  system
• Identification of all uncertainty sources
• Quantification of each uncertainty source
• Specification of equipment
• Actual circumstances
• Calculation of the total uncertainty
• Compliance test for uncertainty and response
  time
• Calculation of statistical data for QAL3

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EN 14181 approach QAL2 (1)

• After installation and every 3/5 years
• Calibration
• Accredited laboratory
• At least15 parallel measurements with Standard
  Reference Method (SRM) in 3 days within 4 weeks
• Sampling system included
• Calculation of calibration line (yabx)
• Implementation of calibration line
• Determination of the valid calibration range

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EN 14181 approach QAL2 (2)

• Test for variability
• compliance test for uncertainty
• Functionality tests (see AST)

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EN 14181 approach QAL3

• Periodic test for on going quality control by
  operator
• Zero and span check with control gasses
• Evaluation of responses with Cusum/Shewart cards
• Action when limits (QAL1) are exceeded
• Adjustment of settings of analyser
• Maintenance
• Check on operation of AMS within valid
  calibration range
• Less than 40 of measurements outside valid range
• 5 weeks less than 5 of measurements in a week
  outside valid range

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EN 14181 approach AST (1)

• Yearly verification test
• Functionality test
• Inspection of sampling system for leakages and
  contamination
• Inspection on alignment of in-situ measurements
• Check on responstime and linearity
• Check on documentation (log books, maintenance an
  functionality reports)
• Serviceability

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EN 14181 approach AST (2)

• Verification measurements
• Accredited laboratory
• 5 parallel measurements with Standard Reference
  Method (SRM) in 1 day
• Check on validity of calibration line

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EN 14181 approach

• four Quality Assurance Levels (QAL)
• QAL1-3
• Annual Surveillance Test (AST)