GRIMM Sky OPC

The GRIMM Sky OPC is an optical particle counting instrument. It works by combining a laser, mirror and detector to measure the scattering off particles. The laser is focused at the centre of the measuring cell, which is the channel where the particles travel through. Further information, including calibration certificates, can be found on the ARSF website: ​GRIMM Sky OPC.

Data format

The data format is a comma separated (csv) file which contains the particle counts at the resolution set during collection. It also contains GPS position and time stamps for each measurement epoch.

The column headings are (we think):

Date

Time

Latitude

Longitude

Speed

Course

Altitude

Satellites

GPS quality

Channel

>0.25

>0.28

>0.3

>0.35

>0.4

>0.45

>0.5

>0.58

Channel

>0.65

>0.7

>0.8

>1

>1.3

>1.6

>2

>2.5

Channel

>3

>3.5

>4

>5

>6.5

>7.5

>8.5

>10

Channel

>12.5

>15

>17.5

>20

>25

>30

>32

All heading values are in µm.

The entries themselves are straight particle counts.

Specifications

The instrument has 32 channels or "bins" of particle sizes, ranging from 0.25um up to 32um, and is capable of measuring up to 2 million particles per cubic litre.

The air is pumped into the instrument via an inlet nozzle.

It can be operated at different time resolutions ranging from 1 second to 60 minutes.

Internal info

Internal information including processing
Information on the GRIMM portal