# Research Note — 2026-06-02 (field-logic refresh)

> **Status: Material protocol improvement**

## Confirmed facts
- NIOSH’s occupational EMF manual continues to distinguish spot measurements, walkthrough surveys, area monitoring, source surveys, and personal monitoring as different measurement families. [^1]
- NIOSH hazard-surveillance material treats walkthrough surveys as screening tools for ambient magnetic fields that should lead to follow-up personal monitoring when needed, rather than as a substitute for individual exposure characterization. [^2]
- NIOSH field work examples reinforce that probe support, orientation, sampling interval, and meter response class matter enough to be logged explicitly if the data are going to be compared later without nonsense creeping in. [^3]
- NIOSH waveform-characterization work shows that ordinary ELF magnitude readings can miss static-field, harmonic, and non-sinusoidal features near worker locations. [^4]
- EPA’s Northwest Indiana contacts page still lists Victoria Wittig, Ph.D. as the Northwest Indiana Urban Waters Ambassador at Purdue University Northwest in Hammond, and it was last updated January 30, 2026. [^5]
- EPA’s Grand Calumet River AOC page still splits Junction Reaches into the IHC south of Columbus Drive, the West Branch between Indianapolis Boulevard and the IHC, and the East Branch between the IHC and Kennedy Avenue; it also says Junction Reaches construction is scheduled to begin in Fall 2026. [^6]
- EPA’s Grand Calumet River AOC page says Lake George Canal monitoring continues through 2027 with possible follow-on remediation in 2028. [^6]
- NIPSCO’s system-upgrades page says crews may document the property’s current state with photos or video, perform preliminary work such as locating and marking underground utilities, and temporarily block streets, lanes, or driveways. [^7]
- NIPSCO’s gas-meter-info page says AMI rollout uncovered a limited number of pre-existing gas-meter component mismatches, affecting less than 1% of natural gas customers, and that the issue was not caused by AMI itself. [^8]

## Practical interpretation
- The pilot is now strong enough to treat four things as first-class metadata everywhere: `measurement_mode`, `method_family`, `meter_response_class`, and `peak_capture_mode`.
- Route screens should stay as screening layers, not final exposure estimates. That keeps walkthroughs useful without pretending they are personal exposure.
- Waveform follow-up belongs only on repeated hotspots or source-adjacent stops, and it should stay separate from the ordinary ELF series.
- East Chicago / Hammond / Whiting corridor context should keep cleanup timing separate from source state, and NIPSCO meter correction should stay separate from both.

## Material improvement made
- Added a concise note that explicitly separates AMI-linked meter correction from EMF signal.
- Reinforced the method-family and waveform-diagnostic split so the field docs keep favoring measurement discipline over story-time.
- The existing protocol already points in this direction, but the new NIPSCO meter-correction context is worth making explicit in its own note.

## Hypotheses
- If future routes overlap AMI correction work, the new note will prevent billing anomalies from being mistaken for exposure anomalies.
- The current protocol probably benefits more from metadata discipline than from any new sensor or bigger map.

## Sources
- [^1]: https://www.cdc.gov/niosh/docs/98-154/
- [^2]: https://stacks.cdc.gov/view/cdc/198423
- [^3]: https://stacks.cdc.gov/view/cdc/198316/cdc_198316_DS1.pdf
- [^4]: https://stacks.cdc.gov/view/cdc/198316
- [^5]: https://www.epa.gov/urbanwaterspartners/program-contacts-northwest-indiana-indiana
- [^6]: https://www.epa.gov/great-lakes-aocs/remediation-and-restoration-projects-grand-calumet-river-aoc
- [^7]: https://www.nipsco.com/services/work-in-your-neighborhood/system-upgrades
- [^8]: https://www.nipsco.com/campaigns/meter-info