Lots of checksum errors occur between readings.
This is just an example:
[...]
found start char
found second char
Framelen OK
got 40 chars stream
Checksum failure
Sum: 970 - check: 48
[1] skip char 0x1A
[1] skip char 0x49
[1] skip char 0x7
[1] skip char 0x3D
[1] skip char 0x0
[1] skip char 0xF6
[1] skip char 0x0
[1] skip char 0xF
[1] skip char 0x0
[1] skip char 0x2
[1] skip char 0x0
[1] skip char 0x1
[1] skip char 0x0
[1] skip char 0x2
[1] skip char 0x0
[1] skip char 0xD2
[1] skip char 0x2
[1] skip char 0x25
[1] skip char 0x0
[1] skip char 0x0
[1] skip char 0x91
[1] skip char 0x0
[1] skip char 0x4
found start char
found second char
Framelen OK
got 40 chars stream
---------------------------------------
Concentration Units (standard)
PM 1.0: 36 PM 2.5: 48 PM 10: 52
[...]