(a)
(b)
(c)
(d)
Figure 10: Results of linear fittings in different relative humidity (RH) ranges for 1-hour averaged data: (a) SDS011 (Nova Fitness), (b) ZH03A (Winsen), (c) PMS7003 (Plantower), and (d) OPC-N2 (Alphasense). in the brackets indicates the number of samples used for fitting.