Environmental Monitoring: An Automation Journey
What’s changed in 30 years: many online measurements, periodic stack testing, parameter and in-process monitoring. Readings now in minute and second points, not daily or occasionally. Electronic log sheets, PI system, factors in spreadsheets/XML, electronic compliance databases. Expectations have also changed: static emission permits, reduced averaging periods, customer expectations, and scorecards. Measurements (e.g., emissions): in amount, time; what’s hard in a paper mill: many assets into a report, reports change, also things change in time. Spreadsheets are difficult to manage, especially when multiple people are involved.
Keys to success: best practices for capital projects: define scope and boundaries (clearly separate out what you “can do” from what you “will do”, document what’s out of scope) and multi-discipline teams (boundary spanners). Best practices for software development: standarize, document detailed design, generalize algorithms with parameters, generalize/pass with attributes and meta-data, and implement check list.
What you need: lots of PI tags. All real-time data: processes, digital states, continuous emission monitors, calculated values, calculation parameters. Special PI tags: raw inputs, filtered input (performance equations), potential to emit (example turning heat off under boiling pot that continues to boil), final aggregated value (hourly, daily, monthly), and golden tags (overrides).
Units of measure: does a unit of measure match PI tag? Wet vs dry measurements—be specific. Be consistent with abbreviation standards. Reconcile data: acquire, clean, overwrite and identify as gospel to prevent multiple interpretation problems. Gap calculations can aid check-out matching data, check how PI tags are calculated. Dump report: first one with all possible calculations, is only place you can go to see what’s really happening; all others are generated against that and created as user reports.
Summary: Build a cross-functional team, use best practices.
