Define the question before measuring
Particle sensors can reveal timing and relative changes, but low-cost devices do not identify composition or health risk by themselves.
Capture a useful baseline
Record the exact location, date, current weather or equipment state, recent activities and the first visible, audible, sensory or measurable change. Keep one unaffected reference point.
Safe observations to repeat
- Record activities and windows
- Compare indoor and outdoor trends
- Avoid disturbing suspect materials for testing
Compare supporting and weakening evidence
Supports the pathway
- Peaks align with a repeatable activity
- Multiple sensors show similar timing
- Ventilation changes the decay curve
Weakens the pathway
- The sensor is contaminated or saturated
- No timing relationship exists
- Only one device reports the event
Interpret the result conservatively
Look for a repeatable relationship between trigger, location, timing and change. Treat exceptions as useful evidence rather than forcing every event into one explanation.
Escalation boundary
Smoke, fire, combustion or hazardous-material disturbance requires immediate safety action and professional guidance.
Close the loop
If work is performed, repeat the same observation under a comparable trigger and through the original lag window. Record both recurrence and non-recurrence events.
Primary references for this topic family
These references ground the general building-science or safety context. They do not diagnose a specific house, replace local requirements or certify a repair.
