Real-Time Measurements of Black Carbon Indoors and Outdoors: A Comparison of the Photoelectric Aerosol Sensor and the Aethalometer

Figures & data

FIG. 1 Diurnal variation of PAS and Aethalometer readings (January-March 2000). Relative standard errors (not shown) ranged from 2–4% for the Aethalometers and 3–11% for the PAS instruments (N = 15,523 5-minute averages).

TABLE 1 Spearman correlations between instruments

Comparison of Instruments/Locations	N	Winter	N	Spring	N	Summer	N	Fall
Aeth A rec room vs. Aeth B utility	21159	0.91
PAS 2000 A rec room vs. PAS 2000 B utility	16750	0.81
PAS 2000 A rec room vs. Aeth A rec room	19245	0.69
PAS 2000 B utility vs. Aeth B utility	16132	0.77
PAS 1001i in vs. PAS 2000 out			12153	0.63
PAS 1001i in vs. Aeth A in			18350	0.44	21992	0.37	17030	0.82
PAS 2000 A out vs. Aeth B out			12332	0.52	19872	0.33	13859	0.64
PAS 2000 A out vs. Aeth A in			12628	0.46	22743	0.31	14136	0.55
Aeth A in vs. Aeth B out			12602	0.64	22056	0.60	24172	0.79
PAS 1001i in vs. PAS 2000 in					23833	0.75	14283	0.55
PAS 2000 A in vs. Aeth A in					23210	0.39
PAS 2000 A in vs. Aeth B out					20441	0.34
PAS 2000 A in vs. PAS 2000 B out					21458	0.60

FIG. 2 PAS (top) and Aethalometer (bottom) around Christmas 1999, and (bottom).

FIG. 3 Woodburning on the night of January 29, 2000 as detected by the outdoor Aethalometer and PAS 2000 instrument.

FIG. 4 Comparison of PAS signal to Aethalometer values for the “woodburning” periods (8 PM to 4 AM on Friday, Saturday, and Sunday evenings) between December 22, 1999 and February 27, 2000.

FIG. 5 Outdoor and indoor Aethalometer and PAS readings during morning rush hour on February 7, 2000.

FIG. 6 Comparison of the outdoor PAS 2000 with the Aethalometer for the period January–February, 2000, during the 6–9 AM rush hour on weekdays.

FIG. 7 Decay rates of indoor Aethalometer and PAS readings after a 1-minute burn of a Citronella candle in the basement utility room.

TABLE 2 Comparison of concentrations with and without four sources active

				Percentile
Variable/location	N	Mean	SD	25th	Median	75th	90th
Outdoor baseline
Aethalometer outdoors (ng/m^3)	32716	507	444	254	411	626	930
PAS 2000 outdoors (fA × 10)	29563	3	8	1	1	3	7
Woodburning (Winter evenings)
Aethalometer outdoors (ng/m^3)	3522	905	1015	361	557	1058	1859
PAS 2000 outdoors (fA × 10)	2837	16	24	1	6	20	45
Autos (Morning rush hours)
Aethalometer outdoors (ng/m^3)	934	1279	907	665	976	1635	2706
PAS 2000 outdoors (fA × 10)	950	28	27	10	17	37	68
Indoor baseline
Aethalometer indoors (ng/m^3)	22147	183	148	84	147	241	358
PAS 1001i indoors (fA)	22147	4	6	1	2	6	9
PAS 2000 indoors (fA × 10)	22147	3	5	1	1	6	11
Citronella candle
Aethalometer indoors (ng/m^3)	591	7547	7557	2017	4781	10584	18369
PAS 1001i indoors (fA)	540	157	158	41	102	228	357
PAS 2000 indoors (fA × 10)	485	258	258	51	159	395	661
Cooking
Aethalometer indoors (ng/m^3)	887	404	502	125	254	467	858
PAS 1001i indoors (fA)	836	11	.10	6	8	13	25
PAS 2000 indoors (fA × 10)	801	12	7	6	11	16	21

TABLE 3 Relationships between PAS and EC (or BC) measurements in previous studies (fA/μg/m³)

Study/Source	Monitor type
Dahmann (2002)	KrCI		Hg	KrBr
Monitor serial number	142	155	655	AQM
Mischkammer Dortmund (August 1999)	4.5	5.2	4.9	4.3
Mischkammer Dortmund (Feb. 2000)	8.8	9.4	12.1	11.5
Mischkammer Dortmund (Sept. 2000)	9.1	10.1	10.1	8.0
Vlischkammer Dortmund (Dec. 2000) (est.)	10	10	9	9.5
Mischkammer Dortmund (Feb. 2001) (est.)	15	20	8	15
Betriebshof OPNV (Nov. 1999)	8.0	7.9		4.3
Eisenbahn Tunnel (May 2000)		9.5	4.0
Verladeranmpe Ost, Brauerei (Jan. 2001)	4.7
Mean (SD)	8.6 (3.5)	10.3(4.6)	8.0(3.1)	8.8 (4.2)
Junker (2000)				14.0 (2.5)
Weingartner (1995)			27 ^a
Saathoff (2003)	27 (6) ^b
Marr (2004)	7–70
This Study
(Woodsmoke)
Weekends, 8 PM–4 AM, Winter only
Reston outdoors (Nov.–Dec. 1999)	1.1
Reston outdoors (Jan.–Feb. 2000)	2.3
Reston indoors (Nov.–Dec. 1999)	2.1		28.5
Reston indoors (Jan.–Feb. 2000)	3.3		76.7
Mean (SD)	2.2 (0.9)		52.6 (34.1)
(Autos)
Weekdays, 6–9 AM
Reston Outdoors (July–Dec. 1999)	1.2
Reston Outdoors (Jan.–May 2000)	2.1
Reston Indoors (July–Dec. 1999)	2.9		24.4
Reston Indoors (Jan.–May 2000)	3.3		32.8
Mean (SD)	2.4 (0.9)		28.6 (5.9)
Frying	2.1		24.5
Citronella candle	3.6		21.2

Junker , M. , Kasper , M. , Roosli , M. , Camenzind , M. , Kunzli , N. , Monn , Ch , Theis , G. and Braun-Fahrlander , C. 2000 . Airborne Particle Number Profiles, Particle Mass Distributions and Particle-Bound PAH Concentrations Within the City Environment of Basel: An Assessment as Part of the BRISKA Project . Atmos. Environ. , 34 : 3171 – 3181 . [CROSSREF] [CSA]

 Web of Science ®Google Scholar

Weingartner , E. , Keller , C. , Sahel , W. A. , Baltensperger , U. and Burtscher , H. 1995 . Field study of Vehicle Emission Factors in a Road Tunnel . J. Aerosol Sci. , 26 ( Suppl. 1 ) : S669 – S670 . [CROSSREF] [CSA]

 Google Scholar

Saathoff , H. , Naumann , K.-H. , Schnaiter , M. , Schock , W. , Weingartner , E. , Baltensperger , U. , Kramer , L. , Bozoki , Z. , Pöschl , U. , Niessner , R. and Schurath , U. 2003 . Carbon Mass Determinations During the AIDA Soot Aerosol Campaign 1999 . J. Aerosol Sci. , 34 : 1399 – 1420 . [CROSSREF] [CSA]

 Web of Science ®Google Scholar

Marr , L. C. , Grogan , L. A. , Wohrnschimmel , H. , Molina , L. T. , Molina , M. J. , Smith , T. J. and Garshick , E. 2004 . Vehicle Traffic as a Source of Particulate Polycyclic Aromatic Hydrocarbon Exposure in the Mexico City Metropolitan Area . Environ. Sci. Technol. , 38 ( 9 ) : 2584 – 2592 . [PUBMED] [INFOTRIEVE] [CROSSREF] [CSA]

 PubMed Web of Science ®Google Scholar