Comprehensive Characterization of Original 10-Stage and 7-Stage Modified Berner Type Impactors

Figures & data

FIG. 1 Scheme used to calibrate stages 7–10 of the original BLPI, using charged particles and applying the calibration method of Hillamo and Kauppinen (1991).

FIG. 2 Scheme used to calibrate stages 7–10 of the original BLPI without using charged particles, applying the APS calibration method.

FIG. 3 Experimental scheme for calibrating Stages 1–3 of the 7-stage modified impactor.

TABLE 1 Basic parameters of the original BLPI25/0.018, measured under standard conditions

Stage	D (mm)	No	S (mm)	Re	P (kPa)	Stk50	D50 (μm)
1	0.289	262	0.99	461	17.74	0.198	0.026
2	0.315	127	0.95	872	29.90	0.213	0.062
3	0.343	65	0.74	1565	47.34	0.234	0.110
4	0.426	25	1.01	3275	77.19	0.235	0.173
5	0.531	16	1.24	4106	95.23	0.204	0.262
6	0.686	16	1.70	3178	100.47	0.194	0.460
7	0.711	46	2.28	1066	101.11	0.190	0.890
8	1.21	33	2.96	874	101.26	0.202	1.77
9	2.18	20	3.48	800	101.30	0.202	3.40
10	5.15	6	5.98	1129	101.32	0.190	6.80
preimpactor	14.60	1	—	—	101.32	0.200	13.70
*Pressure below the final stage of BLPI is 7.5 kPa.

FIG. 4 Collection efficiency of stages 1–10 of the original BLPI using both charged particles and APS.

FIG. 5 Stokes numbers measured for stages 1–10 of the original BLPI using both charged particles and APS.

TABLE 2 Basic parameters of the 7-stage modified BLPI, measured under standard condition

Stage	D (mm)	No	S(mm)	Re	P (kPa)	Stk	D (μm)
1	0.290	65	0.74	1917	91.40	0.198	0.207
2	0.315	127	0.95	886	93.30	0.234	0.329
3	0.289	262	0.99	459	94.50	0.191	0.498
4	0.711	46	2.28	1066	100.47	0.190	0.890
5	1.206	33	2.96	874	101.11	0.202	1.770
6	2.178	20	3.48	800	101.26	0.202	3.400
7	5.150	6	5.98	1129	101.30	0.190	6.800
preimpactor	14.60	1	—	—	101.32	0.200	13.70
*Pressure below the final stage of modified BLPI is 81.1 kPa.

FIG. 6 Mean aerodynamic particle diameters of stages 1–3 of the modified BLPI.

FIG. 7 Stokes numbers of stages 1–3 of the modified BLPI.

FIG. 8 Original BLPI particle losses measured under dry conditions (15% RH) and wet conditions (>80% RH).

FIG. 9 Modified BLPI particle losses measured under dry conditions (15% RH) and wet conditions (>80% RH).

TABLE 3 Averages and standard deviations of particle losses in each stage of the original and modified BLPIs obtained under dry and wet conditions

Losses (%)	Dry conditions		Wet conditions
	BLPI	Modified BLPI	BLPI	Modified BLPI
Stage 3	38 ± 3	—	37 ± 18	—
Stage 4 (1)	19 ± 2	10.8 ± 0.4	17 ± 11	3.1 ± 2.0
Stage 5 (2)	13 ± 4	8.9 ± 1.0	4.3 ± 2.3	1.7 ± 1.7
Stage 6 (3)	6.6 ± 3.7	6.4 ± 1.4	0.9 ± 0.4	1.0 ± 0.7
Stage 7 (4)	12 ± 5	14.7 ± 3.1	0.7 ± 0.4	1.3 ± 0.3
Stage 8 (5)	15 ± 7	10.0 ± 0.3	1.4 ± 0.8	1.7 ± 1.2
Stage 9 (6)	32 ± 13	8.4 ± 1.6	8.6 ± 6.5	8.2 ± 4.3

Hillamo , R. E. and Kauppinen , E. I. 1991 . On the Performance of the Berner Low Pressure Impactor . Aerosol Sci. Technol. , 14 : 33 – 47 .

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