Table I.
Occurrence of major change points (CP) in particulate matter fraction <1 μm diameter (PM1) signal for Sensor A, together with time-stamp data recovered from the air cleaning unit (ACU)
| CP | CP epoch | CP time and date | Significance (P-value) | Time-stamp recovered from ACU | Reason for change |
|---|---|---|---|---|---|
| CP1 | 497 | 08:17 (3rd Aug) | <0.001 | 08:16 (3rd Aug) | ACU switched off |
| CP2 | 935 | 15:35 (3rd Aug) | <0.001 | 15:34 (3rd Aug) | ACU switched on |
| CP3 | 1092 | 18:12 (3rd Aug) | <0.001 | N.A. | Not known |
| CP4 | 1982 | 09:02 (4th Aug) | <0.001 | 09:05 (4th Aug) | ACU speed setting adjusted |
| CP5 | 2389 | 15:49 (4th Aug) | <0.001 | N.A. | Not known |