Table 1.

Number of measured data points (each corresponding to a 1-min measurement), data coverage of the 50 low-cost measurement units, percentage of data over LOD, and a bias correction factor. Units’ names starting with V denote units measuring during the first year, names starting with P units measuring during the second year.

Unit #	# Data Points	Coverage [%]	>LOD [%]	Corr. Factor	Unit #	# Data Points	Coverage [%]	>LOD [%]	Corr. Factor
V03	171319	100	83.2	0.41	P01	227379	100	20.0	0.18
V04	172430	100	16.3	0.47	P02	224369	100	51.0	0.20
V05	169578	99.5	5.5	0.40	P03	225808	100	39.7	0.22
V06	172710	100	34.7	0.29	P04	215369	95.9	13.0	0.29
V07	84731	92.3	81.6	0.41	P05	224224	100	58.1	0.25
V08	173872	100	4.3	0.53	P06	224292	100	37.8	0.27
V09	172299	100	51.4	0.41	P07	214569	100	66.7	0.27
V10	185767	100	82.8	0.41	P08	150726	66.7	0.8	0.72
V12	171244	100	15.2	0.31	P09	222425	100	18.6	0.28
V13	171412	100	1.8	0.41	P10	138294	63.8	15.9	0.25
V14	172625	100	90.3	0.34	P11	220149	98.6	95.3	0.24
V15	173688	100	4	0.46	P12	224304	100	55.8	0.36
V16	170445	100	3.8	0.52	P13	220931	100	19.6	0.29
V17	99435	57.8	100	0.30	P14	221274	99.2	55.0	0.21
V18	172537	100	17.3	0.47	P15	202146	98.3	63.3	0.25
V19	175178	92.9	3.7	0.67	P16	226502	97.1	64.5	0.27
V20	106170	94.2	0.4	0.59	P17	212246	97.3	59.4	0.26
V21	172716	100	39.9	0.3	P18	217567	100	90.9	0.24
V22	128105	71.3	13	0.35	P19	111800	100	12.7	0.34
V23	174482	100	4.8	0.49	P20	102458	98.9	79.9	0.16
V24	170041	100	56.2	0.39	P21	216764	99.1	1.5	0.56
V25	180491	100	74.9	0.36	P22	216647	99.9	3.7	0.27
V26	185397	100	8.9	0.44	P23	214108	99.2	1.7	0.96
V27	181548	100	44.7	0.27	P24	187046	100	27.0	0.33
					P25	159439	99.8	67.5	0.15
					P26	200203	91.5	99.9	0.17